Studies on the contractile activity and ultrastructure of the boar testicular capsule

Abstract

The ultrastructure and the spontaneous and drug-induced contractility of the testicular capsule of 18 boars were investigated. Isometric recordings were obtained in vitro using strips of the tunica albuginea isolated from various regions of the testis. Maximal contractile activity was found in the strips of the posterior border of the testis, in which the histological studies (light and electron microscopy) showed abundant typical smooth muscle cells distributed in layers parallel to the testicular long axis. These cells were largely aggregated in the inner layer of the testicular capsule, which displayed contractile activity similar to that of the entire tunica albuginea. The outer layer of the tunica albuginea was almost totally devoid of smooth muscle fibres and showed little or no contractility. The spontaneous contractions were rhythmic and exhibited an amplitude of 20--70 mg and a frequency of 5--30 contractions/10 min. Norepinephrine, acetylcholine and oxytocin all produced an increase of the contractility of the tunica albuginea, consisting mainly in a rise of the tone.

Fluctuations in Rat Testicular Interstitial Oxygen Tensions Are Linked to Testicular Vasomotion: Persistence after Repair of Torsion1

“…Recently, Bergh et al [17] used two laser-Doppler probes to simultaneously examine vasomotion in two different sites of the same testis and found that vasomotion-induced variations in microvascular blood flow were generally not correlated between the two sites. This suggests that vasomotion is induced by local factors and is not due to a general effect such as pulsatile contraction of the testicular capsule [22].…”

Histomorphological studies of the testis and male genital ducts of Supachai's caecilian, Ichthyophis supachaii Taylor, 1960 (Amphibia: Gymnophiona)

“…; Ohanian et al . ). In addition, accumulation of secretory fluid from the seminiferous tubules contributes to the pressure gradient that promotes transport of spermatozoa out of the testis (Leeson and Cookson ; Setchell et al .…”

The effect of norepinephrine, isoprenaline and acetylcholine on the testicular and epididymal circulation in the pig

“…A rich autonomic nerve supply to the vas deferens and the caudal epididymis was described in a number of animals including the pig (Ratnasooriya et al 1979). The inner layer of the tunica albuginea also contains numerous autonomic nerves (Ohanian et al 1979;Langford et al 1976; Waites et al 1975). On the other hand considerable variation between species exists concerning the autonomic innervation of the testicular vessels.…”

“…They suggested that the vascular smooth muscles of the testicular artery in the ram, rat, rabbit and pig have many fewer a-receptor sites than have smooth muscles of higher regions of the same artery. It should be emphasized that the rich sympathetic nerve supply in the inner layer of the tunica albuginea (Langford et al 1976;Ohanian et al 1979) can influence the inflow of blood to the testis (Waites et al 1975). Damber & Janson (1978) observed vasoconstriction in the epididymis.…”