Exogenous GnRH overrides the endogenous annual reproductive rhythm in green iguanas, Iguana iguana.

Female green iguanas, Iguana iguana, were caught in Belize, Central America (17 degrees N), in December, at the onset of seasonal gonadal activity. The animals were immediately transferred to San Diego (32 degrees N). Ovarian follicular development continued, with peak plasma hormone levels measured in January and February; 200 pg/ml for progesterone (P) and 800 pg/ml for total estrogens (Et = estradiol [E2] + estrone [E1]). E2 was the predominant estrogen throughout the cycle. Follicular atrophy was indicated in April with circulating progesterone and estrogen levels decreasing to baseline (refractory phase) levels (P = 20 pg/ml; Et = 50 pg/ml). Approximately midway through the refractory phase of their annual reproductive cycle (late May), either the D-Arg6 analog of Chicken II or mammalian GnRH was administered via intraperitoneal osmotic pumps for 14 days to nine females. The analog of chicken II induced a fivefold increase in total circulating estrogens within 3-4 days after implantation. Both continuous and pulsatile delivery of the chicken II analog produced a similar pattern of steroidogenic response. A radical sham control animal showed no increase in steroidogenesis. Mammalian GnRH produced a pattern of similar duration, although the magnitude of the steroidogenic response was only half that produced by the chicken II analog. Estrogen titers approached baseline levels in all treatment groups two days after treatment ceased. Progesterone levels increased in all treatment groups during the delivery of exogenous GnRH, although the increases were not consistent. Untreated male cagemates housed with treated females exhibited increased territoriality, courtship behavior, and mating, which began on day 4 or 5 of the treatment period. The control female was not courted by its male cagemate.

Non-invasive assessment of endocrine differences in day-old chicks (Gallus domesticus) by analysis of the immunoreactive oestrogen excreted in the egg.

Oestrone, oestradiol and an uncharacterized polar fraction of oestrogenic substances were monitored by radioimmunoassay in Day-0 domesticated chickens (Gallus domesticus) after routine 21.5-day artificial incubation. Paired adrenals and gonads, blood serum and in-ovo excrement (allantoic urates plus cloacal expressions) were collected from 9 female and 10 male chicks. All samples were homogenized, hydrolysed and extracted with ether. Component oestrogens were isolated by celite:ethylene glycol column co-chromatography before assay. All egg excretory oestrogen measurements were higher (P less than 0.001) in females than in males. Oestradiol was the major excretory oestrogen in both sexes; oestradiol:oestrone ratios (mean +/- s.e.m.) in females and males were 18.45 +/- 2.42 and 3.03 +/- 0.37, respectively. Females had higher (P less than 0.01) total oestrogens for gonadal and adrenal homogenates and for blood serum samples than did the males; oestradiol was generally the major component.

A comparison of three methods of hydrolysis for estrogen conjugates.

The efficiencies for estrogen conjugate hydrolysis were compared between enzyme hydrolysis, acid solvolysis and a new method, ammonolysis. Samples included: 1) crystalline 1,3,5(10)-estratriene-3, 17 beta-diol disulfate (estradiol 3,17-disulfate), 2) squirrel monkey urine collected following an intravenous injection of [2,4,6,7-H] 1,3,5(10)-estratriene-3,17 beta-diol (estradiol) and 3) a pool of human pregnancy urine. Ammonolysis demonstrated a significant increase over the other techniques in "free" estrogen yields, specifically, from estradiol 3,17-disulfate.

Surgical anesthesia in turkeys with thialbarbital sodium.

Thialbarbital sodium was found to be a reliable and economical general anesthetic for domesticated turkeys. Despite shortness of action of the initial dose, surgical anesthesia was maintained longer than 2 hours by intermittent infusion via a brachial vein cannula. The drug was reconstituted just before use (66 mg/ml) with sterile 1% saline solution. Rapid smooth induction was produced with an initial dosage of 30 mg/kg for hens and 26.5 mg/kg for toms, when administered within a 30- to 60-second interval. Supplemental infusion of the drug in increments of 0.25 to 1.5 ml was used to sustain the desired level of deep narcosis. The occurrence of respiratory failure was considerably less for thialbarbital than with pentobarbital sodium. Recovery was rapid and smooth.