Drug Name Erythromycin

Sympathetic Transmitter Substances Whereas acetylcholine (see p. 98) serves as the chemical transmitter at ganglionic synapses between first and second neurons, norepinephrine (= noradrenaline) is the mediator at synapses of the second neuron (B).
Two additional uses are cystinuria and rheumatoid arthritis. In the former, formation of cystine stones in the urinary tract is prevented because the drug can form a disulfide with cysteine that is readily soluble. In the latter, penicillamine can be used as a basal regimen.

 

The endogenous male gonadal hormone is the steroid testosterone from the interstitial Leydig cells of the testis. Testosterone secretion is stimulated by hypophyseal luteinizing hormone (LH), whose release is controlled by hypothalamic GnRH (gonadorelin). Release of both hormones is subject to feedback inhibition by circulating testosterone.
When depletion of NaCl and water (EFV reduction) occurs as a result of diuretic therapy, the body can initiate counter-regulatory responses (B), namely, activation of the renin-angiotensin- aldosterone system. Because of the diminished blood volume, renal blood flow is jeopardized.