The relationship between hypothyroidism and disturbance of the hypothalamo-hypophysial-adrenal axis was investigated using adult male rats. Hypothyroidism was produced by administration of 4-methyl-2-thiouracil (thiouracil) in the drinking water for 2 weeks. Hypothyroidism decreased adrenal weights to 57% of controls and plasma concentrations of corticosterone to 48% of controls. The changes in...

Sexually mature rams were left intact, castrated (wethers), castrated and implanted with testosterone, or castrated, implanted with testosterone and pulse-infused every hour with LHRH. Serum concentrations of LH increased rapidly during the first week after castration and at 14 days had reached values of 13.1 +/- 2.2 ng/ml (mean +/- s.e.m.) and were characterized by a rhythmic, pulsatile patter...

The plasma concentration of growth hormone fluctuates rhythmically over a 24 h period; in humans a major peak of release follows the onset of sleep and smaller peaks occur during ‘unstressed sedentary wakefulness’ (Parker et al. 1979). It can also be altered acutely by insulin-hypoglycaemia, amino acids, neurotransmitters or their precursors agonists or antagonists and by some peptides. These c...

Lampreys, one of the remaining two living jawless vertebrates, carry great weight in study vertebrate evolution. They have a long history dating back to Devonian but left scarce fossil record. So far, only five unequivocal lampreys been described, which four are Paleozoic. Mesomyzon Chang, Zhang & Miao, 2006, known Mesozoic lamprey bridging Paleozoic and extant relatives, was originally conside...

Ellis et al. (l), Li and Papkoff (2) and Ellis (3) have reported changes in biological activity and electrophoretic behavior after treatment of growth hormone with acidic and alkaline buffers, and Lazo-Wasem and Graham (4) have studied the stability of growth hormone prepared by different procedures. Recently, it has been shown (5) that highly purified preparations of growth hormone are contami...

We previously isolated a novel dodecapeptide containing a C-terminal -Arg-Phe-NH(2) sequence, SIKPSAYLPLRF-NH(2) (RFamide peptide), from the Japanese quail (Coturnix japonica) brain. This novel quail peptide was shown to be located in neurons of the paraventricular nucleus (PVN) and their terminals in the median eminence (ME), and to decrease gonadotropin release from cultured anterior pituitar...