Background The intrarenal renin–angiotensin system contributes to hypertension by regulating sodium and water reabsorption throughout the nephron. Sex differences in the intrarenal components of the renin–angiotensin system have been involved in the greater incidence of high blood pressure and progression to kidney damage in males than females. Objective This study investigated whether there is a sex difference in the intrarenal gene expression and urinary excretion of angiotensinogen (AGT) during angiotensin II (Ang II)–dependent hypertension and high-salt (HS) diet. Methods Male and female Sprague-Dawley rats were divided into 5 groups for each sex: Normal-salt control, HS diet (8% NaCl), Ang II–infused (80 ng/min), Ang II–infused plus HS diet, and Ang II–infused plus HS diet and treatment with the Ang II receptor blocker, candesartan (25 mg/L in the drinking water). Rats were evaluated for systolic blood pressure (SBP), kidney AGT mRNA expression, urinary AGT excretion, and proteinuria at different time points during a 14-day protocol. Results Both male and female rats exhibited similar increases in urinary AGT, with increases in SBP during chronic Ang II infusion. HS diet greatly exacerbated the urinary AGT excretion in Ang II–infused rats; males had a 9-fold increase over Ang II alone and females had a 2.5-fold increase. Male rats displayed salt-sensitive SBP increases during Ang II infusion and HS diet, and female rats did not. In the kidney cortex, males displayed greater AGT gene expression than females during all treatments. During Ang II infusion, both sexes exhibited increases in AGT gene message compared with same-sex controls. In addition, HS diet combined with Ang II infusion exacerbated the proteinuria in both sexes. Concomitant Ang II receptor blocker treatment during Ang II infusion and HS diet decreased SBP and urinary AGT similarly in both sexes; however, the decrease in proteinuria was greater in the females. Conclusion During Ang II–dependent hypertension and HS diet, higher intrarenal renin-angiotensin system activation in males, as reflected by higher AGT gene expression and urinary excretion, indicates a mechanism for greater progression of high blood pressure and might explain the sex disparity in development of salt-sensitive hypertension.

Guided inquiry is an active learning technique featuring collaborative group learning with a structured set of models and highly structured questions for students to discuss and answer. Moving this technique to an online delivery format presents challenges, leading to questions about the effectiveness of this technique during online instruction. This study looked at the synchronous online delivery of a sliding filament theory guided inquiry activity (Brown 2015) and scores on related exam questions in anatomy classes at Salt Lake Community College. Students who participated in the guided inquiry activity had a median score of 79% on questions related to the sliding filament theory of muscle contraction while those that did not participate in guided inquiry had a median score of 61%, revealing a medium effect on student test scores. This suggests that the guided inquiry activity was successful at improving student understanding and retention when delivered in the online teaching environment.

The coronavirus pandemic (COVID-19) pointed out new challenges to teaching in laboratory-based disciplines, such as chemistry, biology, and biochemistry with on-site practical sessions interrupted or suspended during 2020 and 2021. Observation and experimentation are part of education in science-based disciplines and provide necessary skills for professional and academic careers. In an effort to solve this disruption to experimental observations, we designed a set of home-based experiences related to chemistry and biochemistry. These included visual identification of lipids, sugars, proteins, and DNA in biological samples using materials easily found at home, such as alcohol, soap, and oil, among others. Each activity was documented with smartphones and discussed in a final portfolio. Fifty-two students were part of an introductory cell biochemistry course. The home-based laboratories were organized into 2.5-h sessions that included a lab session, a post lab session, and a period for preparing the experiment at home. Thirty-six (17 men and 19 women) students answered a survey designed to assess three major domains: (1) student’s demographics and home environment, (2) general perceptions of the laboratory activities, and (3) specific perceptions of each laboratory activity. Sixty two percent of the students thought that these activities helped them to understand how to isolate and identify macromolecules. Eleven percent said these home activities did not contribute to their understanding while 27% stated the activities were not significant for the topic. We conclude that, although the addition of in-house experiments provides a complementary tool for understanding the main concepts in biochemistry along with improving skills in scientific thinking, this should be accompanied by a good feedback mechanism from the instructors. In addition, student to student interaction should be part of the at home activities to increase student motivation. A Flipped laboratory methodology plus tools where metacognition is evaluated, appear to be appropriate to promote the understanding of concepts in the context of the laboratory. And although some aspects of the experimental experience can be substitute with online resources and in home experiences, others can only be achieved by the in-person experience.

We examined if changes in blood pressure and proteinuria during chronic salt intake exhibit sex disparities in age‐matched male (♂; N=10) and female (♀; N=10) Sprague‐Dawley (SD) rats subjected to either normal (0.7% NaCl) or high salt (8% NaCl) diets for 2‐weeks. Metabolic studies, systolic blood pressures (SBP) measured by tail‐cuff method and proteinuria in 24‐h urine samples, were performed. Baseline SBP was not different between genders (♂:119.1±3 vs. ♀:119.0±4 mmHg) or after 2‐weeks on HS diet (♂:129.0±5 vs. ♀:125.6±6 mmHg). HS intake induced proteinuria in both sexes; however it was greater in male than in female rats [Day ‐1(♂:5±1 vs. ♀:3±1); Day 9 (♂:36±3 vs. ♀:17±2 mg/day); p<0.01]. By day 13, body weights were higher in ♂ than ♀ rats; however there was no difference with salt load [(male NS: 330±8 versus male HS: 324±7 g); ♀ NS: 217±12 vs. ♀ HS: 226±4 g)]. There were no sex dependent differences in food intake after it factored by body weight (♂ NS: 11±1 g/kg BW; ♂ HS: 12±1 g/kg BW; female NS: 11±2 g/kg BW; female HS: 13±1 g/kg BW; p=no significant). SBP under HS intake did not exhibit sexual dimorphism; however the augmented proteinuria in male rats may reflect a greater predisposition to develop renal injury with high salt consumption than female rats.Grants from the APS (2009 Frontiers in Physiology Research Host Awardees Program); NIH (P20‐RR‐017659; Tulane‐BIRCWH K12HD043451 award).

Collecting duct (CD) renin is upregulated during Ang II‐dependent hypertension. In this study we examined if CD renin exhibits sex differences during changes in salt intake in 19 Sprague‐Dawley rats distributed in 4 groups [1) Controls male (n=5); 2) Controls female (n=5); HS male (n=5); and HS female (n=4) fed a normal and HS diet (8% NaCl). Baseline systolic blood pressure (SBP) was not different between males and female rats (males: 116±3 vs. female: 119±2 mmHg) nor after 2‐weeks fed a HS diet (male 126±2 vs. female: 128±2 mmHg). Although renin mRNA and protein levels examined by qRT‐PCR and Western blot in renal medullary tissues were similar in male and female rats under control conditions [Controls male: mRNA= 1.0±0.4 AU; protein=1.0±0.1 DU vs. Controls female: mRNA=0.3±0.1AU; protein=0.8±0.1 DU)]; HS diet intake significantly increased the CD renin transcript and protein levels in females but not in male rats [mRNA=(HS male: 1.5±0.1 vs. HS female: 3.4±0.6 AU); protein= (HS male: 1.0±0.3 DU vs. HS female: 1.8 ±0.7 DU). These data suggest that although there is not sex difference in CD renin gene expression under basal conditions, HS intake appears to stimulate renin in distal nephron segment only in female rats. Future studies are planned to determine whether HS intake during chronic Ang II infusion leads to sexual dimorphisms of blood pressure during Ang II‐dependent hypertension.