To investigate a mode and a site of action of inhibin on FSH and LH secretion, in vivo and in vitro effects of porcine follicular fluid (PFF) on FSH and LH secretion were studied in male rats. PFF administered i.v. suppressed basal FSH levels for 1-8 hr, but did not alter LH levels. On the contrary, PFF given either 1 or 6 hr in advance, suppressed LH-RH stimulated LH responses as well as LH-RH...

Viscum album (mistletoe) has been documented as a traditional treatment of diabetes. In acute 20-min tests, 1-10 mg/ml aqueous extract of mistletoe evoked a stepwise 1.1- to 12.2-fold stimulation of insulin secretion from clonal pancreatic B-cells. This effect was abolished by 0.5 mM diazoxide and prior exposure to extract did not alter subsequent stimulation of insulin secretion induced by 10 ...

The influence of cyclic AMP on cartilage degradation was investigated by using phosphodiesterase inhibitors [theophylline and 3-isobutyl-1-methylxanthine (IBMX)], forskolin (which activates the catalytic subunit of adenylate cyclase) and cyclic AMP analogues (dibutyryl and 8-bromo). Breakdown was assessed by quantification of proteoglycans released into the media of 8-day bovine nasal-septum ca...

Single islet cells in monolayer cultures of neonatal rat pancreas were microinjected with the fluorescent dye Lucifer Yellow CH and the cultures were observed by combined phase contrast and fluorescent microscopy. The dye spread from an injected cell directly into neighboring islet cells, and successive microinjections of dye into different cells defined territories comprised of 2-6 communicati...

In the title compound, C(23)H(39)N(3)O(2), the amide O atoms are displaced by 1.020 (1) and 1.211 (1) Å from the mean plane of the central pyridine ring. In the crystal, mol-ecules are connected by weak C-H⋯O hydrogen bonds between methyl-ene groups in the isobutyl substituents and the amide O atoms.

OBJECTIVES Recently, we showed that some new synthetic compounds structurally related to cilostamide (4-(1,2-dihydro-2-oxoquinolin-6-hydroxy)- N-cyclohexyl-N-methylbutanamide), a selective phosphodiesterase 3 (PDE3) inhibitor, produce inotropic effect comparable to that of IBMX (3-isobutyl-1-methylxanthine), a non-selective PDE inhibitor, but with differential chronotropic effect. In this inves...

Sections of posterior intestine of the euryhaline killifish Fundulus heteroclitus adapted to sea water were stimulated by the calcium ionophore ionomycin (1 micromol l(-1)) in combination with agents to elevate intracellular cyclic AMP levels, 0.5 mmol l(-1) dibutyryl-cyclic AMP (db-cAMP) with 0.1 mmol l(-1) 3-isobutyl-1-methylxanthine (IBMX). Intestinal bag preparations from recently fed anima...

the feasibility of extractive reaction of methacrylic acid from aqueous solution using a quaternary amine, tri–octyl methyl ammonium chloride (tomac) as an extractant, was studied. the diluents chosen in the present work belong to different chemical classes, n–butyl acetate, carbon tetrachloride, isoamyl alcohol, methyl isobutyl ketone, and toluene. the effect of initial acid concentration in t...