Ultrastrukturno i morfološko istraživanje endotelnih stanica kapilara grudnih mliječnih žlijezda Wistar štakora tijekom reprodukcijskog ciklusa.

The ultrastructure and morphometry of the endothelial cells of pectoral mammary gland capillaries of female Wistar rats were studied through the reproductive cycle with an electron microscope and image analyser. Subendothelial spaces were absent in the mammary gland capillaries. The density of pinocytotic vesicles (PV) in the capillaries (number of PV per µm2 of endothelial cytoplasm) was significantly increased during pregnancy, reaching maximum values during lactation, and which subsequently decreased during the post-wening stage. The capillaries showed the maximum changes of PV during pregnancy and lactation, with two- and four-fold increases during the respective periods. The density of mitochondria and the length of marginal folds and microvillus processes were also increased significantly (P>0.05) during pregnancy and lactation. The length of marginal folds and microvillus processes were increased two-fold during the lactating period. It is assumed that the ultrastructural changes of endothelial cells of mammary gland capillaries are closely related during the reproductive cycle, and certainly with the functional demand of the mammary glands.Uporabom elektronskog mikroskopa i analizatora slike istraživane su ultrastruktura i morfometrija endotelnih stanica kapilara grudnih mliječnih žlijezda ženskih Wistar štakora tijekom reprodukcijskog ciklusa. Gustoća pinocitotskih mjehurića (PV) u kapilarama (broj PV po µm2 endotelne citoplazme) značajno je porasla tijekom gravidnosti i dosizala najveće vrijednosti u laktaciji, te postupno opadala u razdoblju nakon odbića. Broj PV povećao se dva puta u gravidnosti, a četiri puta u laktaciji. Gustoća mitohondrija i duljina rubnih nabora i broj mikrovila također su značajno (P>0.05) porasli tijekom graviditeta i laktacije. U laktaciji su duljina rubnih nabora i mikrovila bili dva puta veći. Pretpostavljamo da su ultrastrukturne promjene endotelnih stanica kapilara grudnih mliječnih žlijezda usko povezane sa reprodukcijskim ciklusom, a sigurno su povezane s funkcionalnim potrebama mliječnih žlijezda

A simple method for the specific detection of Ren-1 renin

A simple method for the specific detection of Ren-1 renin.BackgroundRen-1 and Ren-2 renin are expressed in the kidneys of all mice and in the submandibular gland of several mouse strains. The present study determined the usefulness of modified periodic acid silver-methenamine (PAM) staining for the specific detection of Ren-1 renin.MethodsConventional paraffin sections were prepared from kidneys of ICR, BALB/cA, C57BL/6Cr, C3H/HeN, DBA/2Cr, angiotensin II type 1a receptor gene knockout (AT1aKO) mice, Wistar rats and a human, and submandibular glands of C57BL/6Cr and DBA/2Cr mice. Sections were analyzed for the presence of renin using PAM and immunohistochemistry. PAM reactions were terminated at generally or weakly intense (weak PAM staining; W-PAM). In addition, kidneys of DBA/2Cr mice were fixed using various fixatives (formalin, PFA, PLP, Zamboni's, Bouin's, or Carnoy's) and treated using identical procedures.ResultsAlthough PAM-positive reactions were observed in juxtaglomerular (JG) cells, W-PAM reactions were particularly specific for these cells. These findings were observed in all mouse strains. Immunohistochemistry using mirror sections suggested that a W-PAM–positive reaction detected renin. This hypothesis was confirmed by the results from AT1aKO mice. Briefly, W-PAM detected an expansion of renin-positive areas in AT1aKO mice. Rat and human kidneys and mouse submandibular glands were negative for W-PAM. Levels of JG cell detection by W-PAM were similar in samples fixed in formalin, PFA, PLP, or Zamboni's.ConclusionsThe present findings show that W-PAM can identify Ren-1 renin, but not Ren-2, rat or human renin. The W-PAM method is useful for the specific detection of Ren-1 renin