About the Lab

The Yallampalli Lab conducts basic sciences and perinatology research. Our research is focused in six main areas.

Fetal Programming of Adult Health and Diseases

Fetal Programming of adult health and diseases, with special emphasis on the role of sex-steroid hormones on the regulation of mechanisms underlying hypertension and diabetes. We use low-protein diet model to study its effects during pregnancy and assess the consequences in the adult offspring. Hypertension is more severe and the onset is earlier in males compared to females and in both sexes testosterone levels are elevated. An antiandrogen can reverse the hypertension in females. Majority of the hypertensive symptoms are due to endothelial cell dysfunction and increased angiotensin responsiveness. In addition, we are currently investigating what are the maternal factors that may be responsible for programming in the offspring. Although several agents may be involved, we found testosterone and angiotensin II are elevated. We are investigating what are the mechanisms that underlie these elevations in the mother. More importantly how these factors are influencing the placental functions and whether they are transported to the fetus to program the outcomes. Many aspects of maternal changes to the low-protein diet are still unknown and need detailed research effects.

Vascular Adaptions During Pregnancy

Vascular adaptions during pregnancy and implications for pathophysiology of preeclampsia. Maternal vasculature reacts by decreasing vascular resistance for the increased blood volume and increased cardiac output. The mechanisms in these adaptions are not fully investigated. We have found that peptides of Calcitonin gene-related peptide (CGRP) family appear to play a major role in these adaptations, besides nitric oxide. Levels of peptides in circulation and their receptors in the resistance arteries are elevated and the post receptor signaling is also increased. Currently we are working on the specificity of receptor component association and their tissue specificity, such as mesenteric vs uterine artery. Further we are assessing how factors like TNFα (known to be upregulated in preeclampsia) alter the peptide actions in vasculature.

CGRP Family Peptides during Early Pregnancy

The involvement of CGRP family peptides during early pregnancy. One of the family member, Intermedin, appears to significantly influence on both decidual cell and trophoblast cell functions during implantation and placental formation. Trophoblast cell invasion is regulated by Intermedin, currently we are exploring the mechanisms in the process. One of the family member, Intermedin, appears to significantly influence on both decidual cell and trophoblast cell functions during implantation and placental formation. Trophoblast cell invasion is regulated by Intermedin, currently we are exploring the mechanisms in the process.

Role of Nitric Oxide

Role of nitric oxide as a host defense molecule in reducing urogenital infections especially through the regulation of CD55. Further we are currently exploring the role of CD55, CD46 and other complement regulatory proteins in modulating complement cascade events during pregnancy and especially in placenta.

Placental Perfusion System

Placental perfusion system and its use in assessing the trans-placental transfer of drugs and nutrients. This system can be utilized to assess a variety of substances for their ability to transfer from maternal to placental circulation.

Vascular Dysfunction in Preeclampsia

Mechanisms underlying the vascular dysfunction in preeclampsia using omental arteries. Currently we obtain omental arteries from normal and preeclamptic patients for studying a variety of mechanisms that regulate vascular (dys) function, such as CGRP peptides, Prostaglandins, Soluble FLt-1, PLGF, and nitric oxide.