Stimulation of food intake and weight gain in mature female rats by bovine prolactin and bovine growth hormone.

Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.

2-Hydroxy-4-(methylthio) butanoic acid is a naturally occurring methionine precursor in the chick.

The objective of these experiments was to determine the origin of 2-hydroxy-4-(methylthio)-butanoic acid (HMB) detected in the liver and excreta of chicks that had never been fed Alimet (an 88% aqueous solution of HMB) or MHA (an 86% calcium salt of HMB). Gas chromatography and mass spectrometry were used to identify HMB in these birds. A normal biochemical pathway of 5'-deoxy-5'-methylthioadenosine (MTA) is proposed as the source of naturally occurring HMB. Studies of conversion of [methyl-14C]MTA to L-methionine by chick liver enzymesØe showed that radiolabeled HMB and 2-oxo-4-(methylthio)butanoic acid (keto-methionine) were synthesized during the reaction. Specific radioactivities of labeled HMB and keto-methionine showed that HMB is not synthesized from keto-methionine. Fractionation studies indicated that radiolabeled HMB formed from [14C]MTA could be used in the synthesis of L-methionine in the presence of peroxisomes and/or mitochondrial enzymes. In this way, HMB synthesized from MTA by chick liver enzymes functions as a precursor of L-methionine and as an intermediate in a naturally occurring pathway for the synthesis of L-methionine in the chick.

Analysis of lung air from patients with bronchogenic carcinoma and controls using gas chromatography-mass spectrometry.

Volatile metabolites present in expired lung air were collected by odor sampling techniques and analyzed by gas chromatography-mass spectrometry. The study population included controls matched for age and smoking history with patients newly diagnosed with lung carcinoma. Significantly greater concentrations of o-toluidine were found in the lung air of patients with lung carcinoma than either age-matched or younger controls. Aniline was present in half of the patient population but absent in age-matched controls.

Conditioned aversions to an intravascular odorant.

The odorant allyl sulfide (essence of garlic) dissolved in a corn oil vehicle was injected into rats to induce a conditioned aversion. In subsequent two-choice drinking tests, rats injected with odorant and lithium chloride, and rats injected with odorant and saline avoided drinking from a water bottle paired with the odorant. Because allyl sulfide and saline injections produced symptoms of malaise, we suspect that the odorant served as its own unconditioned stimulus. Rats injected with vehicle and saline showed no differential behavior. In a second experiment, gas chromatography indicated that allyl sulfide was present on the rat's breath within 3 minutes of injection, and was detectable for up to 5 hours post-injection. We conclude that conditioned aversions can be obtained to an intravascular odorant and that one route by which such odorants reach the nose is the breath.

Volatiles of exogenous origin from the human oral cavity.

The volatiles found in the headspace above male and female saliva were examined by combined gas chromatography--mass spectrometry. This had led to the identification of a number of constituents of exogenous origin. The most likely source of these products are atmospheric and water pollutants as well as food stuffs and cosmetic products. Volatiles from saliva represent a potential medium for the detection of reproductive states as well as local and systemic diseases. Consequently, knowledge of compounds not arising from the body's metabolic process if important to prevent their identification as anomalous metabolites.

Quantitative differences in volatiles from healthy mouths and mouths with periodontitis.

It has been suggested that orally derived volatile aromatic amines may be of possible diagnostic use and may contribute to the etiology or pathogenesis of periodontal disease. Using gas chromatography and gas chromatography/mass spectrometry, we identified and quantitated pyridine and picolines in the headspace of incubated whole saliva from healthy and diseased subjects. The oral health of subjects was evaluated by four standard oral-health indices. Volatile aromatic amines were virtually absent from subjects with healthy oral cavities, but were present in the oral cavities of subjects with periodontitis to the extent of 636.4 (SEM 154.7) ng/5 mL of saliva. Pyridine and picolines in saliva of diseased subjects may be related to the disease process.