Drug Name Levlen

The cleavage product, salicylic acid, retains pharmacological activity. In certain cases, drugs are administered in the form of esters in order to facilitate absorption (enalapril enalaprilate; testosterone undecanoate testosterone) or to reduce irritation of the gastrointestinal mucosa (erythromycin succinate erythromycin).
The effect of ACh elicited at receptors on the ganglionic neuronal membrane can be imitated by nicotine; i.e., it involves nicotinic cholinoceptors. Ganglionic action of nicotine. If a small dose of nicotine is given, the ganglionic cholinoceptors are activated. The membrane depolarizes partially, but fails to reach the firing threshold.

 

Negative feedback control of gonadotropin release can be utilized to inhibit the ovarian cycle. Administration of exogenous estrogens (ethinylestradiol or mestranol) during the first half of the cycle permits FSH production to be suppressed (as it is by administration of progestins alone).
The opposing effects on smooth muscle (A) of ?-and ?-adrenoceptor activation are due to differences in signal transduction (p. 66). This is exemplified by vascular smooth muscle (A). ?1-Receptor stimulation leads to intracellular release of Ca2+ via activation of the inositol trisphosphate (IP3) pathway.