Aquaporin-1 expression in visceral smooth muscle cells of female rat reproductive tract.

The aquaporins (AQ-s) are a group of intrinsic membrane proteins which facilitate movement of water across cell membranes; their recent identification in the kidney has led to the reappraisal of the mechanisms and pathways of water movement across epithelia. Aquaporin-1, (CHIP-28) is reported distributed in cardiac myocytes and vascular smooth muscle cells of large arteries. A related protein, AQ-4, has been identified in the sarcolemma of skeletal muscle fibres. We report aquaporin expression in the cell membrane of smooth muscle cells of the rat genital tract; fluorescence immunohistochemistry of rat uterine (fallopian) tube and vagina demonstrated AQ-1 in visceral smooth muscle of these tissues. In the uterine tube, AQ-1 labelling is most pronounced in the innermost longitudinal and the inner cells of the circular muscle layer and is absent from the outer longitudinal muscle layer of the myosalpinx. The possibility of a specific role for AQ-1 in tubal transport by altering the tubal luminal diameter during the estrus cycle is suggested.

Human endometrial perfusion after tubal occlusion.

We examined variations in human endometrial microvascular perfusion across one menstrual cycle in women who had undergone tubal ligation and did not report unusual menstruation. Endometrial red blood cell flux was monitored by laser Doppler fluxmetry via a fibreoptic probe atraumatically inserted transvaginally into the uterus of each of 13 conscious volunteers. The observations obtained have been compared with those previously reported from a matched control group of women [B.J. Gannon et al., Hum. Reprod., 12, 132-139 (1997)]. Women who had undergone tubal occlusion for sterilization exhibited greater endometrial perfusion during menstruation (cycle days 0-5), at the time of ovulation (cycle days 13-16) and in the late secretory phase (cycle days 23-28) than occurred in controls. In addition, vasomotion in the study group was lower than that in controls in the early and late secretory phase (cycle days 17-22 and 23-28). Tubal occlusion appeared to alter endometrial perfusion. It is possible that the reported menstrual changes in women following tubal ligation are a consequence of altered endometrial perfusion; a possible causative relationship is discussed.

PIP: Tubal ligation has been associated with an increase in postsurgical dysmenorrhea or menorrhagia. The present study used laser Doppler fluximetry to measure endometrial perfusion in 13 South Australian women who had undergone tubal ligation an average of 5.7 years earlier and did not report subsequent menstrual dysfunction. This technique provides a measure of the flux of red blood cells through a small sphere of tissue immediately adjacent to a probe placed over the endometrium. Measurements were taken once a week over 4 weeks (usually 1 menstrual cycle) and were compared with those obtained earlier by the authors from a matched control group of 19 women. Women who had undergone tubal occlusion exhibited greater endometrial perfusion than controls during menstruation (cycle days 0-5), at the time of ovulation (cycle days 13-16), and in the late secretory phase (cycle days 23-28). In addition, vasomotion was lower in the study group than among controls in the early (cycle days 17-22) and late (cycle days 23-28) secretory phase. Further exploration of the potential pathophysiology associated with tubal sterilization is warranted.

Endometrial perfusion across the normal human menstrual cycle assessed by laser Doppler fluxmetry.

This study investigated variations in microvascular perfusion of human endometrium across the menstrual cycle, using a laser Doppler technique to assess red blood cell (RBC) flux. Endometrial RBC flux was monitored by laser Doppler fluxmetry via a fibre optic probe inserted transvaginally into the uteri of 19 conscious normal volunteer women, on four occasions at weekly intervals over one menstrual cycle. Regional variation in RBC flux was investigated in 16 surgical patients under general anaesthesia and in five excised uteri. Endometrial perfusion exhibited short-term temporal variations consistent with the cardiac cycle and often also showed vasomotion (5-12 cycles/min). Mean endometrial perfusion differed between phases of the menstrual cycle in conscious women, being highest during early proliferative and early follicular phases. There were no significant regional differences in local mean endometrial perfusion in anaesthetized patients. No evidence of endometrial ischaemia/reperfusion episodes was found in any subject using this technique. This study provides benchmark data of variations in RBC flux per unit volume of tissue in the luminal approximately 1 mm of endometrium, across the normal human menstrual cycle. Flux values were highest at times associated with endometrial growth and preparation for implantation, indicating that RBC flux may be a useful parameter for assessment of endometrial physiology.

Nonlaser videolaparoscopic surgery for ectopic gestation.

The potential of nonlaser videolaparoscopic surgery for ectopic gestation in a metropolitan public hospital was assessed by the review of the last 16 consecutive women presenting to the author with either a ruptured or an unruptured ectopic pregnancy. Ten of the 16 were treated by the videolaparoscopic techniques of either salpingotomy or aquaexpression, removal of the ectopic pregnancy and pelvic lavage; there were no intra or postoperative complications. HCG levels were monitored to extinction in all but one woman who had a coexistent intrauterine pregnancy. Three of the 10 women have subsequently had intrauterine conceptions and none have had further ectopic gestations. Those women unsuitable for videolaparoscopic therapy had substantial haemorrhage (4), an ovarian ectopic pregnancy (1) and extensive adhesions precluding laparoscopy (1). The techniques of nonlaser videolaparoscopic treatment for tubal ectopic gestation are simple and appropriate in a majority of women presenting with this condition.

Renal clearance of amino acids in pregnancy complicated by preeclampsia.

Renal clearance of most amino acids was increased in the third trimester of pregnancy. The greatest change was with glycine, where clearance increased thirteen-fold and the plasma level decreased. No difference in renal clearance of amino acids was demonstrated in four patients with proteinuric hypertension when compared with that in normal pregnancy. Progesterone, given to non-pregnant women, caused a fall in mean plasma glycine. This was associated with increased renal clearance in 2 out of 3 women, and indicates that progesterone may contribute to the increased renal excretion of some amino acids in pregnancy, probably acting selectively on tubular reabsorption.

Vascular perfusability and capillary macromolecular permeability in the mechanically induced rabbit hydrosalpinx.

The mechanically induced rabbit hydrosalpinx, a frequently studied animal model of human hydrosalpinges, was examined to determine the variations, in vascular perfusion and capillary albumin permeability, which occur in hydrosalpinges. At laparotomy, 4 adult female virgin rabbits underwent isthmic and ampullary occlusion with small tantalum clips. 4 weeks later, fluorescein isothiocyanate-labelled bovine serum albumin (FITC BSA: molecular weight 67,000) was injected intravenously 5 min before oviduct excision. Examination of tubal sections by incident light fluorescent microscopy demonstrated poor interplical vascular perfusability and markedly reduced interplical capillary permeability to FITC BSA in both isthmic and ampullary segments of hydrosalpinx. These observations imply that, in the experimental rabbit hydrosalpinx, interplical deciliation is probably vascular in origin; furthermore the marked decrease in capillary macromolecule permeability may explain the serous fluid collection within the hydrosalpinx. Poor fecundity following microsurgical restoration of tubal patency in hydrosalpinges is possibly due to the failure of this decrease in submucosal capillary perfusability and macromolecular permeability to resolve.

Variations in rabbit oviduct microvascular architecture after ovulation induced by hCG.

Rabbits were induced to ovulate by injection with hCG and vascular corrosion casts of the oviducts were examined by scanning electron microscopy after 24 and 48 h, when the ova would be expected to be at the ampullary-isthmic junction, and traversing the isthmus respectively. At 24 h there was dilatation of the isthmic subserosal venous plexus. It is suggested that venous distension in the isthmic subserosal venous plexus, due to raised venous pressure or to reduced venous wall tone, may occlude the isthmic lumen to ova, and thus explain the known pre-isthmic delay in ovum transport. By 48 h after hCG, distension was no longer evident, consistent with the possibility of ovum transport.

Microvascular architecture of the pregnant rabbit oviduct.

Methyl-methacrylate vascular corrosion casts of the oviducts were prepared in 7 rabbits which were 2-3 weeks pregnant. Scanning electron microscopy of the acrylic casts revealed little change in tubal microvascular connections when compared with control oviducts. Venous distension in the isthmic subserosal venous plexus, ampullary subserosal vasculature and in the fimbrial core was substantially greater than that observed in controls. These changes are interpreted as indicating a sensitivity of tubal microvasculature to the increased levels of circulating placental hormones in pregnancy. The implications of this interpretation in the role of tubal microvasculature at the time of ovulation are discussed.

Fallopian tube microvasculature in the rabbit.

The microvascular architecture of rabbit Fallopian tube isthmic, ampullary and fimbrial regions was examined by the corrosion vascular cast-scanning electron microscope method. The aorta and inferior vena cava of virgin adult female rabbits (2.5-3.5 kg) were cannulated; after blood wash out, methacrylate casting medium was infused via the aorta. After plastic hardening, Fallopian tubes were excised, tissues corroded and casts prepared for scanning electron microscopy. The isthmic myosalpinx is encircled subserosally by an interlocking venous plexus. We suggest that a rise in pelvic venous pressure could lead to a decrease in isthmic luminal diameter and thus act as a sphincter contributing to the known delay in ovum transport at the ampullary isthmic junction. Stereo pairs of photomicrographs showed that isthmic plicae are supplied by arterioles which change little in diameter passing through the tubal wall. Near the apex of a fold, these arterioles terminate in a subepithelial capillary plexus which drains to deep mucosal and plical core venules. In contrast, the ampulla is supplied by smaller and less frequent arterioles. Frequent large venules extending high into the plicae drain the subepithelial capillary plexus. Based on this microvascular architecture, we suggest that the subepithelial capillary plexus of the apical region of the plicae probably contains high pressure blood in the isthmus and lower pressure blood in the ampulla. Therefore, plicae in these regions may be specialised for net luminal fluid secretion and absorption respectively, implying a role for the microvasculature in tubal transport by initiation or modification of fluid flow along the lumen.

Uterine tube microvascular architecture after oophorectomy in the rabbit.

4 adult female virgin rabbits underwent bilateral oophorectomy. 4 weeks later methylmethacrylate corrosion vascular casts of their uterine tubes were prepared. Scanning electron microscopy of the acrylic casts revealed a decrease in the size and number of the large ampullary plical and fimbrial veins which are normally characteristic of these regions. This observation suggests that the reported tubal dysfunction which follows oophorectomy may have a vascular component.

Microvascular architecture of the mechanically induced hydrosalpinx in the rabbit.

This study was undertaken to document changes in microvascular architecture (MVA) associated with the mechanically induced rabbit hydrosalpinx. Twelve adult female virgin rabbits underwent isthmic and ampullary occlusion at laparotomy, with small tantalum clips. Two or four weeks later, methylmethacrylate vascular casts of the mechanically induced hydrosalpinges were prepared and examined by scanning electron microscopy. This revealed plicae of markedly reduced size projecting into the distended lumen and fewer subepithelial capillaries were cast in the interplical region than in the adjacent plicae. The fluid accumulation in the hydrosalpinx is presumably a net transudate of the tubal subepithelial capillary bed. The large ampullary plical veins seen in controls were absent; the prominent isthmic arteries normally observed were more pronounced and their branching was more extensive. Subserosal veins were more distended over the hydrosalpinx than in adjacent normal isthmus or ampulla. These observations indicate that the major vascular effects of hydrosaplinx formation are an alteration of interplical MVA and subserosal venous dilation, and suggest higher vascular pressure and blood flow in the mechanically induced hydrosalpinx. We speculate that this implies greater epithelial transudation and that maintenance of the hydrosalpinx, in this model, is probably due to microvascular alterations.

Successful pregnancy induced by human menopausal gonadotrophin in a patient with growth hormone deficiency and primary amenorrhoea: case report.

A patient with growth hormone deficiency and primary amenorrhoea became pregnant with the help of human menopausal gonadotrophin. Pregnancy was complicated only by abdominal discomfort due to her very small stature and by moderate oedema. She was delivered of healthy female twins by lower segment Caesarean section at the 37th week.