The influence of a 56-km endurance exercise on cortisol kinetics and production rate was evaluated in six horses administered [3H]cortisol. Exercise resulted in an immediate two- to threefold increase in plasma cortisol, with values returning very rapidly to preexercise levels. During exercise, clearance and steady-state volume of distribution of total cortisol were greatly increased (338 +/- 95 vs. 137 +/- 34 ml.kg-1.h-1 for clearance and 359 +/- 82 vs. 229 +/- 18 ml/kg for volume of distribution), whereas the terminal half-life decreased significantly (0.97 +/- 0.16 vs. 1.55 +/- 0.33 h). The estimated cortisol production rate was 4.41 +/- 1.06 micrograms.kg-1.h-1 at rest and 26.75 +/- 5.11 micrograms.kg-1.h-1 during exercise. We conclude that exercise triggers a large increase (x 6) in the adrenal secretion rate, which is not accurately reflected by the more limited increase (x 2-3) in plasma cortisol concentration, the actual measurement of plasma cortisol clearance being a prerequisite to assessment of adrenal gland function during exercise.

Fourteen newborn calves had low gamma-glutamyl transferase catalytic activity concentration in blood plasma (10 to 31 U/liter). Colostrum intake induced a dramatic increase of plasma gamma-glutamyl transferase activity, which was maximal on the 1st or 2nd day (370 to 5000 U/liter) after birth; then plasma enzyme activity slowly decreased and was stable about 100 U/liter on the 20th day. In two calves given either boiled or synthetic milk, plasma gamma-glutamyl transferase activity was not higher than 25 U/liter. Gamma-glutamyl transferase activity of blood plasma in newborn calves is an easy and inexpensive test of colostrum intake.

The protein and PGE metabolite content of the aqueous humor from untreated and flunixin meglumine pretreated dogs was determined prior to and after anterior chamber paracentesis. In the untreated dogs the concentrations of protein and PGE" metabolite in aqueous humor were greatly elevated secondary to paracentesis. Intravenously administered flunixin meglumine (1.1 mg/kg or 2.2 mg/kg) significantly reduced these inflammatory parameters, confirming that prostaglandins are involved in the stability of the blood-aqueous barrier by paracentesis in the canine eye. The clinical implication of these results is that intravenous adminstration of flunixin meglumine before intraocular surgery should be considered as an adjunct therapy to reduce intraoperative and postoperative uveitis.

In domestic animals, Gamma Glutamyl Transferase is mainly in the kidneys, the pancreas and the intestine; its liver activity is relatively high in cows, horses, sheep and goats and very low in dogs, cats and birds. The use of plasma reference values can help to interpret the variations of serum GGT mainly in hepatobiliary diseases of cattle, sheep, goats and cholestatic disorders of dogs. Urinary GGT is a good test of kidney toxic damage.

The study carried out on rats given orally the n-hexane lipido/sterolic extract of Serenoa repens (LSESR), supplemented with [14C]-labelled oleic or lauric acids or beta-sitosterol, demonstrated that radioactivity uptake in prostatic tissues shows the highest level in the case of administration of LSESR supplemented with [14C]-labelled oleic acid. This was clearly demonstrated on a rat with an induced fibro-muscular hyperplasia of the prostate and by quantitative measurements of radioactivity. Ratios of radioactivity in tissues compared to plasma show an uptake of radioactivity greater in prostate as compared to other genital organs, i.e. the seminal vesicles or to other organs such as liver.