جستجوی مقالات مرتبط با کلیدواژه "collagen type iv" در نشریات گروه "پزشکی"

Nicotine can pass through placental blood barrier and accumulate in the developing organs of fetus. Also, entering the breast milk, nicotine can have an effect on the neonates. Investigations have showed that collagen IV is one of the most important micro vessels basement membrane components.

In this study, the effect of maternal nicotine exposure in pre and postnatal periods on collagen IV in microvessels of neonatal Balb/C mice brain cortex was studied by immunohistochemistry technique.

24 pregnant Balb/C mice were divided in to 4 groups (6 mice in each group): two experimental and 2 control groups. The mothers in the 1st experimental group were injected 3 mg/kg nicotine intrapritoneally from the 5th day of pregnancy to parturition daily and in 2nd experimental group the same procedure was repeated to the 10th day after parturition (lactation). The control groups received the same volume of normal saline during the same time. 10 days after delivery, the brain tissues of newborns were isolated. Then, prepared blocks from fixed brain were cut serially for immunohistochemical assay.

The findings of the present study indicated that collagen IV reaction in microvessels basement membrane in the first experimental group increased significantly compared to the first control group (p=0.002). In addition, collagen IV reaction in microvessels basement membrane in the 2nd experimental group increased significantly compared to the 2nd control group (p=0.002). However, no significant difference was observed between the two experimental groups.

These results suggested that maternal nicotine exposure during prenatal period may increase basement membrane collagen IV expression. Also, nicotine increases in maternal breast milk has no effect on basement membrane collagen IV expression.

During nephrogenesis, transition of mesenchyme to the epithelium of tubules and glomeruli occurs via the interaction of ureteral bud and metanephric mesenchyme. The distribution pattern of collagen type IV suggests that a regulated balance of activities is required to facilitate migration of the ureteral bud branches into the mesenchyme and to control early extracellular matrix changes during tubulogenesis. We used a specific antibody for tracing collagen type IV basement membrane during renal tubules morphogenesis.

Twenty female Balb/C mice were divided randomly into 10 groups and were kept until finding vaginal plug was as an indicator of day zero of pregnancy. Twelve pregnant mice were sacrified by cervical dislocation in one of gestational days 13 to 18 and their fetuses were fixed, serially sectioned, and underwent immunohistochemical study for tracing of collagen type IV in basement membrane of glomeruli. The same processes were used for kidneys preparation on postnatal days 5, 10, 15, and 20 in newborns of 2 mothers for each day.

Collagen type IV showed weak reaction on day 14 of gestation in tubular basement membrane. The amount of collagen increased continuously until the following days of fetal life and of the first 5 postnatal days in basement membrane. After this period, collagen type IV reaction was not showed significant change in newborns.

These results indicate that developmental changes in various nephron segments from most immature stages to most differentiated structures are dependent on the collagen type IV expression