ephs@roy..bellcore.com (Barbara Chalfonte) (11/29/89)
We have a _raging_ controversy here that standard sources of information have failed to resolve. Is saliva basic or acidic? I thought acidic, in keeping in line with the rest of the GI tract, my office-mate thought basic, being the exception to the GI tract. So which is it? Having looked at several standard dictionaries, medical dictionaries, and encyclopedias, the conclusion is still unresolved: some say mildly alkaline, others say alkaline in reaction, and others say mildly acidic (pH=6.8). Mostly these sources just don't say. Our stockroom doesn't cater to such nonsense and thus has no litmus paper. What's the real story????? Barb Chalfonte Bellcore MRE 2D-292 445 South Street Morristown, NJ 07960 email: ephs@thumper.bellcore.com PS: The lucky winner with the definitive answer gets to find out _why_ anyone in telecomm & computer research would want to know this...
royf@attctc.Dallas.TX.US (Roy Frederick) (11/29/89)
Quoting from "Clinical Diagnosis by Laboratory Methods" by Todd and Sanford: "The secretion of the salivary glands amounts to about 1500 cc in twenty four hours. It is a colorless, odorless, slightly viscid liquid with alkaline reaction." This edition was copyright in 1946, back when medical tests required labor instead of machines.... According to "Green Leaves of Barley" by Dr Mary Ruth Swope (which may not be completely reliable...) the PH of saliva varies in reaction according to your diet and general health - and may be acid or base. It does seem likely that diet and medical conditions could affect it since normal saliva is fairly close to neutral. Roy Frederick (royf@attctc.UUCP) Dallas County Data Services (214) 653-6340 504 Records Bldg. Dallas, TX 75202
drues@atanasoff.cs.iastate.edu (Michael E. Drues) (11/29/89)
ephs@roy..bellcore.com (Barbara Chalfonte) writes: >We have a _raging_ controversy here that standard sources of information have >failed to resolve. Is saliva basic or acidic? I thought acidic, in keeping >in line with the rest of the GI tract, my office-mate thought basic, being >the exception to the GI tract. So which is it? Having looked at several Well, it's been a while since I took GI physiology but here goes: I think the problem stems from the way you have worded your question. In other words, there's no simple answer. 8^) You see, saliva contains a mishmosh of chemicals which are a function of time of day, phase of digestive cycle and probably the surface temperature of pluto (is there such a thing as a biological constant? probably not) :-) Saliva is a buffered solution. As an engineer, you can think of this as stable equilibrium, i.e., a ball between two hills, no matter which way you push it, it will try to come back to where it started (within limits of course). Ganong, "Review of Medical Physiology", 1987 [this is at the same level as K&R in the C language world :-) ] states: ``The pH of saliva is **about** 7.0'' p.406 The buffers in the saliva try to maintain a neutral pH - at this level, the saliva is saturated with calcium so the teeth do not loose Ca to the oral fluids. The buffers also help neutralize gastric acid and relieve heartburn when gastric juice is regurgitated into the esophagus. To complicate matters further, concentrations of some ions increase and others decrease when flow rates increase or decrease (if you want the details, see Ganong or something). BTW, about 1500 mL of saliva are produced per day. So what does all this mean? Well, suffice it to say, ``The pH of saliva is **about** 7.0'' Of course, you could walk around for a week or so with a digital pH meter in your mouth. I bet you could do an FFT on it and find a cercadian (sp?) rythm!?! Does this help? If there are any GI physiologists or MDs out there who would like to correct me on this, then by all means do. I am afterall merely an engineer. After doing a Ph.D. in Biomedical Engineering, I have come to realize this (EE/CS/Cpr E types listen up!), Whoever designed the human body didn't use anything as simple as V=iR!! And of course if you want to talk about a non-human animal, (i.e., a ruminent- that's like a cow), then *everything* changes! 'nough said. +-----------------------------------------------------------------------+ | // Michael Drues | | \X/ Internet: drues@atanasoff.cs.iastate.edu | | Bitnet: v2.med@isumvs.bitnet | | Pony Express: Dept. of Biomedical Engineering | | 1146 Veterinary Medicine | | Iowa State University | | Ames, Iowa 50011 | | Phone: (515) 294-6520 | +-----------------------------------------------------------------------+
werner@aecom.yu.edu (Craig Werner) (11/30/89)
In article <18383@bellcore.bellcore.com>, ephs@roy..bellcore.com (Barbara Chalfonte) writes: > > We have a _raging_ controversy here that standard sources of information have > failed to resolve. Is saliva basic or acidic? I thought acidic, in keeping > in line with the rest of the GI tract, my office-mate thought basic, being > the exception to the GI tract. So which is it? Actually, yard for yard, most of the digestive tract is basic. True, the stomach is pH 2, and the first third of duodenum is buffered only by the food, which makes it about pH 4-5, but from the common bile duct on, enough bicarbonate is pumped in to put the jejunem, ileum, and colon on the basic side of neutral. Aside from discovering that pH paper tastes horrible, all I can say is that saliva appears to have so little buffering capacity, and is so close to neutral that I only tell that it's between 6.5 and 7.5. My personal guess would be acidic, if only because of the dissolved carbonic acid resulting from the CO2 being exhaled. -- Craig Werner (future MD/PhD, 4.5 years down, 2.5 to go) werner@aecom.YU.EDU -- Albert Einstein College of Medicine (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517) "Viruses do to cells what Groucho did to Freedonia."
larry@kitty.UUCP (Larry Lippman) (12/01/89)
In article <18383@bellcore.bellcore.com>, ephs@roy..bellcore.com (Barbara Chalfonte) writes: > We have a _raging_ controversy here that standard sources of information have > failed to resolve. Is saliva basic or acidic? I thought acidic, in keeping > in line with the rest of the GI tract, my office-mate thought basic, being > the exception to the GI tract. So which is it? Having looked at several > standard dictionaries, medical dictionaries, and encyclopedias, the > conclusion is still unresolved: some say mildly alkaline, others say > alkaline in reaction, and others say mildly acidic (pH=6.8). Mostly these > sources just don't say. The composition and hence pH and electrolyte content of saliva VARIES, depending upon conditions which are usually determined by the RATE of FLOW. A "quiescent mouth" [for lack of a better term :-)] contains saliva which is markedly hypotonic, while a mouth in a state of active salivation contains saliva which is almost isotonic. The pH of typical human saliva in the absence of pathology varies between 6.4 and 7.0. The chief organic constituent of saliva is mucin. > PS: The lucky winner with the definitive answer gets to find out _why_ > anyone in telecomm & computer research would want to know this... I am salivating for your answer. If I might hazard a guess as to _why_, are you perhaps investigating corrosion problems with handsets and their transmitters elements? I bet that a typical transmitter sees its fair share of saliva over its lifetime! <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {allegra|boulder|decvax|rutgers|watmath}!sunybcs!kitty!larry <> TEL 716/688-1231 | 716/773-1700 {hplabs|utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 | 716/773-2488 "Have you hugged your cat today?"
drues@atanasoff.cs.iastate.edu (Michael E. Drues) (12/03/89)
werner@aecom.yu.edu (Craig Werner) writes: > Aside from discovering that pH paper tastes horrible, all I can ^^ ^^^^^ ^^^^^^ ^^^^^^^^ > Craig Werner (future MD/PhD, 4.5 years down, 2.5 to go > werner@aecom.YU.EDU -- Albert Einstein College of Medicine > (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517) Well, this may have been the way to do it in the stone age (atleast before I started grad school (^8 ). Today there is a field of medical technology called BioSensors. There are a whole host of *very* small devices which could be implanted in the mouth to record pH *continuously* over a week or so. Actually, this would be an interesting experiment to undertake. I'd be a bit surprised if the same thing has not already been done (atleast in a bovine or swine model). +-----------------------------------------------------------------------+ | // Michael Drues | | \X/ Internet: drues@atanasoff.cs.iastate.edu | | Bitnet: v2.med@isumvs.bitnet | | Pony Express: Dept. of Biomedical Engineering | | 1146 Veterinary Medicine | | Iowa State University | | Ames, Iowa 50011 | | Phone: (515) 294-6520 | +-----------------------------------------------------------------------+
warg6606@uxa.cso.uiuc.edu (12/06/89)
I had a friend in college who suffered from gastric ulcers because he chewed tobaco. His physician told him that because he "chewed," he was spitting too much. The good doctor's point was that the saliva was required to help neutralize the gastric juices secreted during the chewing. This of course implies that the saliva is alkaline.
eesnyder@boulder.Colorado.EDU (Eric E. Snyder) (12/06/89)
In article <114000002@uxa.cso.uiuc.edu> warg6606@uxa.cso.uiuc.edu writes: > I had a friend in college who suffered from gastric ulcers because >he chewed tobaco. His physician told him that because he "chewed," he was >spitting too much. The good doctor's point was that the saliva was required >to help neutralize the gastric juices secreted during the chewing. This >of course implies that the saliva is alkaline. I find this difficult to swallow. Although saliva many have some buffering capacity, I seriously doubt it is alkaline enough to offset stomach acidity. More likely, the sensation of having some tasty chew in one's mouth increases gastric secretion, possibly resulting in a gastric ulcer. Of course, the nicotine in chewing tobacco also induces increased secretions of various sorts as a pharmacological property of the chemical itself. Put these together and you have a lot better senario for an ulcer than simply spitting too much! FYI: I enjoy a good chew so no flames from people thinking I object to the sport! --------------------------------------------------------------------------- TTGATTGCTAAACACTGGGCGGCGAATCAGGGTTGGGATCTGAACAAAGACGGTCAGATTCAGTTCGTACTGCTG Eric E. Snyder Department of Biochemistry Proctoscopy recapitulates University of Colorado, Boulder hagiography. Boulder, Colorado 80309 LeuIleAlaLysHisTrpAlaAlaAsnGlnGlyTrpAspLeuAsnLysAspGlyGlnIleGlnPheValLeuLeu ---------------------------------------------------------------------------
drues@atanasoff.cs.iastate.edu (Michael E. Drues) (12/07/89)
warg6606@uxa.cso.uiuc.edu writes: > I had a friend in college who suffered from gastric ulcers because >he chewed tobaco. His physician told him that because he "chewed," he was >spitting too much. The good doctor's point was that the saliva was required >to help neutralize the gastric juices secreted during the chewing. This >of course implies that the saliva is alkaline. ^^^^^^^ ^^^^ ^^^ ^^^^^^ ^^ ^^^^^^^^ No, no, no. (Atleast not necessarily). What this implies is that saliva is a buffer solution (which is true). This does *not* imply anything about the pH of the solution (acidic or alykaline). Perhaps you should brush the dust off your old chemistry text and check for your self. 8^) Mike +-----------------------------------------------------------------------+ | // Michael Drues | | \X/ Internet: drues@atanasoff.cs.iastate.edu | | Bitnet: v2.med@isumvs.bitnet | | Pony Express: Dept. of Biomedical Engineering | | 1146 Veterinary Medicine | | Iowa State University | | Ames, Iowa 50011 | | Phone: (515) 294-6520 | +-----------------------------------------------------------------------+
jgk@osc.COM (Joe Keane) (12/09/89)
It's important to remember that the saliva doesn't neutralize the acidity, it buffers it. If the saliva had to neutralize the acidity, it'd have to be pH 12, assuming approximately equal volumes. This is clearly not true. The saliva has a certain pH that it tends to maintain, by buffering. This observation alone doesn't determine saliva's pH one way or the other. Secreting saliva and gastric juices tend to go together, when you're eating something or thinking about it. They're supposed to be mixed together to get the right pH in your stomach. I think the reason chewing tends to cause ulcers is exactly what the doctor said, that you spit out the saliva, and keep producing gastric juices even though there's nothing in your stomach.
warg6606@uxa.cso.uiuc.edu (12/10/89)
I find this difficult to swallow. Although saliva many have some buffering capacity, I seriously doubt it is alkaline enough to offset stomach acidity. More likely, the sensation of having some tasty chew in one's mouth increases gastric secretion, possibly resulting in a gastric ulcer. Of course, the nicotine in chewing tobacco also induces increased secretions of various sorts as a pharmacological property of the chemical itself. Put these together and you have a lot better senario for an ulcer than simply What does nicotine pharmacolgy have to do wth the pH of saliva? I was only relating something that had been told to me, and I believed it relevant to the current topic. At least we both agree that saliva is alkaline. W. R. P. S. Don't get me wrong-I didn't believe it either in terms of the mechanism of chewing causing ulcers, and I think what was responded is much closer to the mark. But I did think it was a cute fallacy! /* End of text from uxa.cso.uiuc.edu:sci.bio */
warg6606@uxa.cso.uiuc.edu (12/19/89)
>If the saliva had to neutralize the acidity, it'd have to be pH
I've had some girlfriends that would make me argue this point!
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