The variations in circulating ecdysteroids and juvenile hormones (JH) in Galleria, from the end of the antepenultimate larval stage until emergence of adults, have been determined. The two hormonal families were extracted separately from the same hemolymph sample and quantified by two radioimmunoassays. Juvenile hormone RIA activity was about 35 nM in larvae of the antepenultimate and penultimate stages. It dropped before each molt and increased thereafter. Moreover, it gradually decreased during the last larval instar. In pupae, it was generally low, but it rose drastically during the late pupal development and in young adults. This rise was very much higher in females than in males. Three different RIA-active compounds were found; they were assumed to be JH-I, JH-II, and JH-III according to their retention times in HPLC. The three compounds were present in almost equal concentration in larvae of the penultimate stage: JH-I predominated, however, during the last larval instar. In late pupae, the main hormone was JH-III both in males and in females. There is no clear relationship between ecdysteroid and juvenile hormone changes, except for a female-specific ecdysteroid rise which coincides with the juvenile hormone release in late pupae. This double hormonal stimulation can be involved in the regulation of vitellogenin synthesis and deposition in oocytes.
50) During a stressful interval
A) TSH stimulates the adrenal cortex and medulla to secrete acetylcholine.
B) the alpha cells of islets secrete insulin and simultaneously the beta cells of the islets secrete glucagon.
C) ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla.
D) the posterior pituitary gland secretes more growth hormones.
E) the calcium levels in the blood are increased due to actions of two antagonistic hormones, epinephrine and norepinephrine.