Myogenic and neurogenic control of electrical and mechanical activity in human oviductal smooth muscle

Abstract

Isolated strips from isthmic and ampullary muscle layers of the human fallopian tube were investigated with the sucrose-gap technique and in organ baths. Generally good correlation existed between electrical and mechanical activity, but dissociation was also noted. The isthmic external longitudinal layer (IEL) was characterized by slow waves of depolarization and broad 'spikes'. Tonic contraction followed depolarization, and phasic waves followed the spikes. In the other layers, regular spikes and phasic contractions dominated. Late in the menstrual cycle, more irregular patterns and slow waves, which could synchronize spike activity, were found. Automaticity tended to be highest in the late proliferative phase. Active response to stretch was best demonstrated in IEL. Excitatory alpha-adrenergic responses (hypopolarization, firing and contraction) to noradrenaline and nerve stimulation dominated in the IEL. In the other layers, beta-adrenergic inhibition prevailed. Non-adrenergic, non-cholinergic neurogenic inhibition was demonstrated. Decrease in spike frequency and hyperpolarization seemed to be as prominent as during beta-adrenergic inhibition. Muscarinic stimulation by acetylcholine was recorded as depolarization, spikes and contraction. However, a role for cholinergic nerves could not be defined. Thus, the human oviductal smooth muscle belongs to the single unit category; its activity can be modified during the menstrual cycle, by stretch and by excitatory and inhibitory nerves.

CB1 Expression Is Attenuated in Fallopian Tube and Decidua of Women with Ectopic Pregnancy

“…Both adrenergic receptors have been identified in the human Fallopian tube and there is evidence of similar adrenergic control of human oviductal smooth muscle activity [16]–[18]. However, CB1 expression has not been demonstrated to our knowledge in the human Fallopian tube or endometrium.…”

Characterization of postsynaptic α‐adrenoceptors in the arteries supplying the oviduct

“…oviductal arteries) are richly innervated by sympathetic nerves (Brunding et al, 1969;Black, 1974). It is well established that the sympathetic nervous system is involved in the control of the contractile activity of the oviduct (Howe & Black, 1973;Rodriguez-Martinez, 1984;Samuelson & Sjostrand, 1986;Isla et al, 1989). This control is also related to the hormonal status through the oestrous cycle, which could influence the catecholamine concentration as well as the receptor predominance (Samuelson & Sj6strand, 1986;Juorio et al, 1989).…”

Structural changes in the oviductal wall during passage of unfertilized cumulus‐Oocyte complexes in mice

“…Faussone-Pellegrini and Bani (1989) indicated that cyclic changes occurred in the structure of the oviduct musculature. It has also been reported that the motility of the oviduct musculature is stimulated by estrogen (Samuelson and Sjostrand, 1986). These data indicate that under endocrine control, the muscle coat of the oviduct changes morphologically and plays an important role in gamete transport and fertilization.…”