Purinergic signalling in the genito-urinary tract
The main objective of this thesis was to examine the role of purinergic signalling in the contraction of the smooth muscle of the genito-urinary tract of laboratory animals and compare it to that of man. It also examined purinergic signalling in the maturation of sperm within the epididymis. The main methodology involved organ bath studies on the functional physiology of smooth muscle contraction, in conjunction with immunohistochemical examination of smooth muscle P2X receptor expression. In Chapter 3, a comparative study of the smooth muscle cells of the testicular capsule or tunica albuginea of the testis from man, mouse, rat and rabbit was made. The smooth muscle cell arrangement was demonstrated by electron microscopy, and the role of purinergic co-transmission in the contraction of this smooth muscle was investigated. Chapter 4 examined purinergic signalling in the contraction of the human vas deferens smooth muscle. P2X receptors are involved in cell-to-cell signalling. Chapter 5 was a comparative study of the expression of P2X receptors on sperm contained within the head and tail of the epididymides of mice, rats, hamsters and man. This study demonstrated changing expression with maturity. Alterations in the relative purinergic and cholinergic components of detrusor contraction have been demonstrated in the over active bladder. Chapter 6 details the partial bladder outlet obstruction model that was developed in the rat. This model demonstrated an up-regulation of the cholinergic component of detrusor contraction with no significant change in the purinergic component, which implied the rat detrusor adapts to outflow obstruction in a different manner to the human detrusor. In Chapter 7, a general discussion of the role of purinergic signalling in the genito-urinary tract is given. The extent of how well the hypothesis was tested is considered in this chapter and future directions are suggested.