Genome-wide association study revealed suggestive QTLs for production and reproduction traits in Indian Murrah buffalo.

The present study was aimed to identify the genome-wide SNPs associated with production and reproduction traits in 96 Indian Murrah buffalo genotyped based on ddRAD approach using Genome-Wide Association Study (GWAS) along with phenotypes of contemporary animals using mixed linear model for production and reproduction traits. A total of 27,735 SNPs identified using ddRAD approach in 96 Indian Murrah buffaloes were used for GWAS. A total of 28 SNPs were found to be associated with production and reproductive traits. Among these, 14 SNPs were present in the intronic region of AK5, BACH2, DIRC2, ECPAS, MPZL1, MYO16, QRFPR, RASGRF1, SLC9A4, TANC1, and TRIM67 genes and one SNP in long non-coding region of LOC102414911. Out of these 28 SNPs, 9 SNPs were found to have pleiotropic effect over milk production traits and were present in chromosome number BBU 1, 2, 4, 6, 9, 10, 12, 19, and 20. SNPs in the intronic region of AK5, TRIM67 genes were found to be associated with milk production traits. Eleven and five SNPs in the intergenic region were associated with milk production and reproduction traits respectively. The above genomic information may be used for selection of Murrah animals for genetic improvement.

Estimation of genetic parameters of growth traits for direct and maternal effects in Murrah buffalo.

An understanding of genetic principles and environmental factors affecting the growth traits is essential to implement optimal breeding and selection programs. Early growth is an indicator of future success in production and reproduction status of dairy animals. In this study, a total of 18,989 records of body weight were used to estimate genetic parameters of body weight at birth (BW), 3 months (3BW), 6 months (6BW), 9 months (9BW),12 months (12BW), 18 months (18BW), 24 months (24 BW), 30 months (3BW), and 36 months (36BW) in Murrah buffalo at ICAR-NDRI Karnal, Haryana, for the period 1974-2019. The genetic parameters were estimated using the average information restricted maximum likelihood (AIREML) procedure by excluding or including maternal effects. Six analytical models were fitted in order to optimize the model for each trait. The most appropriate univariate model was selected based on the log likelihood ratio test (LRT). Influencing factors like calf sex, period of birth, season of birth, and dam's parity were investigated. The results showed that the maternal genetic effects, in addition to direct additive effects, were important for unbiased and accurate genetic parameter estimates of growth traits in Murrah buffaloes. Total heritability estimates h2T1 for BW, 3BW, 6BW, 9BW, 12BW, 18BW, 24BW, 30BW, and 36BW were 0.25, 0.04, 0.14, 0.16, 0.10, 0.15, 0.21, 0.24, and 0.23, respectively. Maternal effect was significant for birth weight and accounted for 13% variation through maternal genetic and 5% variability through maternal permanent environmental effect. Maternal genetic effect was also important for other traits. However, it interfered with the estimates of variance ratios in live weight traits owing to large and negative covariance between direct and maternal genetic effects. Direct genetic correlations between body weight traits were positive and high ranging from 0.10 to 0.94. Results revealed that the Murrah herd has a sizable genetic variability for growth traits and hence, there is sufficient scope for selection for achieving better growth rate if selection in this direction is applied. Owing to higher positive genetic correlation of 6BW with later ages, the scope of indirect selection for optimum growth in later ages can be aimed at by selecting animals for their higher 6-month live weight.

Knowledge and Awareness about Systemic Effects of Periodontal Disease among Medical, Dental and Alternate Medical Practitioners and Their Referral Practice to Periodontists.

In the past few decades, many medical professionals and dentists have paid close notice to their own fields, specializing in medicine pertaining to body and oral cavity respectively. Currently, this void is rapidly closing between all medical specialties, in presence of significant findings that supports association between periodontal disease and systemic conditions. Till now, some practitioners are not aware about the specialties of dentistry that results in improper referral practices. There are few studies on referral practice pertaining to periodontist, not with standing the fact that clear and effective communication between all health practitioners is essential for good practice. A cross-sectional study was carried out to assess the knowledge and awareness about systemic effects of periodontal disease among medical, dental and alternate medical practitioners and their referral practice to periodontist in Kanpur city. This cross-sectional study was carried out using self-reported questionnaire, distributed to 560 practitioners of various medical fields from January 2020 to August 2021. A total of 206(36.8%) Medical, 194(34.6%) Dentists and 160(28.6%) alternative practitioners participated in study. More than half participants agreed about relationship between periodontal diseases and Diabetes Mellitus, Cardio-VascularDisease and Adverse Pregnancy Outcomes. Among all 31.3% showed good knowledge level while 2.7% showed perfect level of practitioner's referral practice to periodontist. Dentists had statistically higher level of awareness compared to physicians. Referral practice to periodontist was deficit by medical and alternate medical practitioners despite of fact; they have good knowledge of relationship between periodontal disease and systemic health. Hence, interdisciplinary dental and medical training of practitioners is recommended.

Udder and teat morphometry in relation to clinical mastitis in dairy cows.

The present study was undertaken to explore the association of occurrence of clinical mastitis with udder and teat morphometry in cattle. The relationship of nine udder and eight teat morphometric traits with the occurrence of clinical mastitis was analysed using a binomial logistic regression model. A significant association of the udder and teat morphometric traits with the occurrence of mastitis was observed both in Karan Fries and Sahiwal cattle. The rear udder height, rear udder width, udder width and fore udder attachment were found to be the important udder morphometric traits associated with the occurrence of mastitis. In both groups, mastitic animals had broader rear udder width, lower rear udder height and loose fore udder attachment with lengthy and thicker teats. The inclusion of udder and teat morphometric traits in the selection and breeding program of Karan Fries and Sahiwal cattle may help in selection of animals for mastitis resistance.

Estimation of genetic parameters for production and reproductive traits in Indian Karan-Fries cattle using multi-trait Bayesian approach.

Estimates of variance components are needed for implementing genetic selection. This study was conducted to genetic parameters for production and reproductive traits on Indian Karan-Fries cattle using multi-trait repeatability animal model. Data collected from ICAR-National Dairy Research Institute, Karnal, India (from 1988 to 2019) were used. Single-trait and multi-trait repeatability animal models were used for parameter estimation. The posterior mean of Heritability estimates for 305-day milk yield (305-DMY), lactation milk yield (LMY), lactation length (LL) were 0.20 ± 0.03, 0.19 ± 0.03 and 0.06 ± 0.02, respectively. For age at first calving (AFC), calving interval (CI), and days open (DO), the posterior mean of heritability estimates were 0.24 ± 0.08, 0.06 ± 0.01, and 0.07 ± 0.02, respectively. The repeatability estimates for 305-DMY, LMY, LL, CI, and DO were 0.37 ± 0.02, 0.34 ± 0.02, 0.15 ± 0.02, 0.09 ± 0.02, and 0.12 ± 0.02, respectively. Genetic correlation between milk production traits (305-DMY, LMY, and LL) was positive and strong (> 0.80). However, the genetic correlation between milk production trait and AFC ranges from - 0.31 to 0.12. Unfavorable strong genetic correlations were observed between production and reproductive traits (CI and DO) with values ranged from 0.5 to 0.7. Phenotypic correlations among 305-DMY, LMY, and LL were generally positive and high. The moderate heritability estimates and potential genetic variation for 305-DMY, TMY, and AFC suggested that genetic gain can be obtained for these traits through genetic selection. Low heritability estimates found for LL, CI and DO, indicating that the possibility of changing these traits through genetic selection is small. High genetic correlation observed between productive and fertility traits were unfavorable. The existed strong genetic and phenotypic correlation estimates between CI and DO indicates that recording only one of them would be sufficient in the herd. As the multi-trait model showed slight improvements in the h2 as well as r estimates for both productive and reproductive traits over univariate analysis, future selection with a multi-trait animal model applying Bayesian approach would be recommended.

Profiling and integrated analysis of whole-transcriptome changes in uterine caruncles of pregnant and non-pregnant buffaloes.

Improved reproductive performance in buffaloes can be achieved by understanding the basic mechanism governing the embryonic attachment and feto-maternal communication. Considering this, trascriptomic profiling and integrative analysis of long intergenic non-coding RNAs were carried out in the uterine caruncles of pregnant and non-pregnant buffaloes. Transcriptome data of pregnant and non-pregnant uterine caruncles after quality control was used to perform the analysis. Total of 86 novel lincRNAs expressed in uterine caruncular tissues were identified and characterized. Differential expression analysis revealed that 447 mRNAs and 185 mRNAs were up- and down- regulated, respectively. The number of up- and down- regulated lincRNAs were 114 and 13, respectively. Of the identified 86 novel lincRNAs, six novel lincRNAs were up-regulated in the pregnant uterine caruncles. GO terms (biological process) and PANTHER pathways associated with reproduction and embryogenesis were over-represented in differentially expressed genes. Through miRNA interaction analysis, interactions of 16 differentially expressed lincRNAs with mi-RNAs involved in reproduction were identified. This study has provided a catalogue of differentially expressed genes and novel regions previously unknown to play a significant role in buffalo reproduction. The results from the current study extends the buffalo uterine lncRNAs database and provides candidate regulators for future molecular genetic studies on buffalo uterine physiology to improve the embryo implantation and successful completion of pregnancy.

A Preliminary Study on the Evaluation of In-vitro Inhibition Potential of Antimicrobial Efficacy of Raw and Commercial Honey on Escherichia coli: An Emerging Periodontal Pathogen.

Periodontitis, a multiple pathogen disease has the latest addition to the family i.e. Escherichia coli as a potential and emerging periodontal pathogen owing to its lipopolysaccharide more potent than Porphyromonas gingivalis, which makes it an emerging threat in periodontal disease. The role of antimicrobial agents in the management of periodontal diseases is of utmost importance. However, in the present scenario, antibiotic resistance is a public health concern now and there are very few options left for treatment. So, honey, a pioneer in traditional medicine was tried in the treatment against Escherichia coli to evaluate and compare the "in-vitro" antibacterial activity and efficacy of raw and commercial honey at different concentrations in comparison to tetracycline as a control on patient-isolated Escherichia coli and the American Type Culture Collection (ATCC) Escherichia coli 25922 strain from 5th Aug 2018 to 15th Feb 2019 at the Department of Microbiology, Rama Medical College, Kanpur (UP), India. In the in-vitro study different concentrations (100%, 75%, 50% and 25% v/v) of raw and commercial honey were studied and sensitivity tests were used to evaluate their antibacterial effect on patient-isolated Escherichia coli and the ATCC Escherichia coli 25922 strain. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) were also determined for raw honey, and commercial honey in comparison to tetracycline. In case of raw honey, zone of inhibition was seen at 100%, 75% and 50% concentration, with maximum inhibition being 27±1.154mm and 23±0.666mm for patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain respectively at 100% concentration, whereas, the commercial honey was effective only at 100% and 75% concentration, with maximum inhibition zone of 13±1.054mm and 17±0.942mm at 100% concentration on patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain respectively. However, no effect was observed at 25% concentration for both raw and commercial honey. The MIC and MBC of raw and commercial honey were determined by the broth dilution method, where raw honey exhibited both MIC and MBC at 512 mg/ml whereas, and commercial honey exhibited MIC at 512mg/ml and MBC at 1024 mg/ml respectively. While comparing the zone of inhibition of raw and commercial honey, it was observed that the raw honey showed almost equivalent potency and efficacy as compared to a positive control tetracycline (2.5%). There was statistically significant difference (p≤0.01) in zone of inhibition of raw and commercial honey at 100% concentration on patient-isolated Escherichia coli and ATCC Escherichia coli 25922 strain. Antimicrobial activity of raw honey at 100% concentration was equivalent to that of tetracycline and was significantly better than commercial honey.

Recent advances on mycotic keratitis caused by dematiaceous hyphomycetes.

Dematiaceous hyphomycetes (DH) are darkly pigmented fungi ubiquitously found all over the world as plant pathogens and saprophytes, and many of the members of this group have emerged as opportunistic pathogens. These fungi are responsible for a wide variety of infections including mycotic keratitis, which is considered as one of the major causes of corneal blindness, particularly in tropical and subtropical countries with an annual global burden of about 1 000 000 patients. The infection is more common in workers working in an outdoor environment. Moreover, trauma is found to be the most important predisposing cause of mycotic keratitis. Considerable delay in diagnosis and scarcity of effective pharmacological drugs are the major factors responsible for increased morbidity and visual impairment. Considering the crucial role of DH in mycotic keratitis, in the present review, we have focused on major DH with special emphasis on their pathogenicity, diagnosis and treatment strategies.

Rpb4 and Puf3 imprint and post-transcriptionally control the stability of a common set of mRNAs in yeast.

Gene expression involving RNA polymerase II is regulated by the concerted interplay between mRNA synthesis and degradation, crosstalk in which mRNA decay machinery and transcription machinery respectively impact transcription and mRNA stability. Rpb4, and likely dimer Rpb4/7, seem the central components of the RNA pol II governing these processes. In this work we unravel the molecular mechanisms participated by Rpb4 that mediate the posttranscriptional events regulating mRNA imprinting and stability. By RIP-Seq, we analysed genome-wide the association of Rpb4 with mRNAs and demonstrated that it targeted a large population of more than 1400 transcripts. A group of these mRNAs was also the target of the RNA binding protein, Puf3. We demonstrated that Rpb4 and Puf3 physically, genetically, and functionally interact and also affect mRNA stability, and likely the imprinting, of a common group of mRNAs. Furthermore, the Rpb4 and Puf3 association with mRNAs depends on one another. We also demonstrated, for the first time, that Puf3 associates with chromatin in an Rpb4-dependent manner. Our data also suggest that Rpb4 could be a key element of the RNA pol II that coordinates mRNA synthesis, imprinting and stability in cooperation with RBPs.

Polymorphism in DNA repair gene BRCA1 associated with clinical mastitis and production traits in indigenous dairy cattle.

The present study was conducted on Karan Fries cows to identify SNPs in breast cancer 1 (BRCA1) gene and their association with inflammation of mammary gland and production traits. Chi square analysis showed significant association of both SNPs i.e. G43737229T (P < 0.01) and G43761121A (P < 0.05) with incidence of clinical mastitis. Logistic modeling showed that GG genotype cows of G43737229T SNP was less susceptible to mastitis in comparison to TT genotype cows as the odds ratio of TT against GG for the non-incidence of mastitis was less i.e. 0.23. Whereas, cows with genotype AA of G43761121A SNP were less prone to clinical mastitis in comparison to GG genotype cows. G-T haplotype and GGTT combined genotype exhibited maximum mastitis incidences. Least squares analysis revealed significant association of G43737229T SNP with total milk yield (P < 0.01), 305 days milk yield (P < 0.01) and lactation length (P < 0.05). The TT and GT genotyped Karan Fries cows were associated with higher milk yields during first and second lactation, as well as with first lactation length. These observations on SNPs, genotypes and combined genotypes of BRCA1 gene and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits.

Genomic divergence reveals unique populations among Indian Yaks.

The present study focused upon identification of genome-wide SNPs through the reduced representation approach and to study the genomic divergence of the Indian yak populations. A total of 80 samples belonging to Arunachali yak (N = 20), Himachali yak (N = 20), Ladakhi yak (N = 20) and Sikkimi yak (N = 20) of India were used in the study. The results of the study revealed a total of 579575 high quality SNPs along with 50319 INDELs in the Indian yaks. The observed heterozygosity was found to be high in Himachali yak, followed by Arunachali yak, Ladakhi yak and Sikkimi yaks. The Sikkimi yaks was found to be genetically distant, followed by Ladakhi yaks which was observed to have some few individuals from Arunachali and Himachali yaks. Arunachali and Himachali yaks are found to get clustered together and are genetically similar. The study provides evidence about the genomic diversity in the Indian yak populations and information generated in the present study may help to formulate a suitable breeding plan for endangered Indian yaks. Moreover, the unique yak populations identified in the study will further help to focus attention for future characterization and prioritization of the animals for conservation purposes through the ddRAD approach.

Transrectal Subharmonic Ultrasound Imaging for Prostate Cancer Detection.

OBJECTIVE: To assess the prostate cancer (CaP) detection rates of contrast-enhanced, transrectal subharmonic ultrasound imaging (SHI). MATERIALS AND METHODS: This IRB-approved study enrolled 55 subjects. The initial 5 subjects were studied for SHI optimization, while the remaining 50 were evaluated with contrast-enhanced sonography using continuous SHI, color, and power Doppler as well as conventional grayscale, continuous color, and power Doppler and SHI combined with maximum flash replenishment. A maximum of 6 directed biopsy cores were obtained from sites of greatest asymmetrical enhancement, followed by spatially distributed cores in a double sextant distribution. Subharmonic time-intensity parameters, including time to peak intensity, peak intensity, and estimated perfusion were also evaluated for each directed biopsy core. Receiver operating characteristic curve analysis and conditional logistic regression were employed to assess the benefit of each modality and the quantitative SHI parameters. RESULTS: Cancer was detected in 22 of 50 subjects. Among subjects with clinically significant CaP (n = 11), targeted cores were more likely to be positive (odds ratio 1.39, P = .02). The majority of patients detected by SHI demonstrated significant CaP (5/8); SHI remained an independent marker of malignancy in a multivariate logistic regression model (P = .027). Receiver operating characteristic curve analysis of imaging findings compared to biopsy results yielded diagnostic accuracies ranging from 0.59 to 0.80 for all imaging modalities with the highest being for quantitative subharmonic perfusion estimates. CONCLUSION: This first-in-humans study provides a preliminary estimate of the diagnostic accuracy of SHI for detection of clinically significant CaP (up to 80%).

Development of PCR based assays for detection of lethal Holstein haplotype 1, 3 and 4 in Holstein Friesian cattle.

Holstein haplotype (HH) 1, 3 and 4 are lethal mutations, responsible for early embryonic losses in Holstein Friesian (HF) cattle, worldwide. Three PCR based assays - tetra Amplification Refractory Mutation System PCR, PCR primer induced restriction analysis and PCR-restriction fragment length polymorphism techniques for screening of HH1, 3 and 4, respectively were developed and validated. During screening, six among 60 HF bulls were found as carrier for either of three mutations. These PCR assays are highly accurate and reproducible and can be used for screening of the haplotypes in HF cattle.

Genome-wide discovery of SNPs in candidate genes related to production and fertility traits in Sahiwal cattle.

The present study was carried out to identify genome-wide genetic markers and variants in candidate genes for production and reproduction traits in Sahiwal cattle using a cost-effective reduced representation sequencing method. A total of 258,231 genome-wide SNPs were identified in Sahiwal cattle with reference to Bos indicus genome, of which 150,231 were novel SNPs. Among the high-confidence SNPs identified, 91.86% and 27.30% were genotyped in 50% and 100% of the samples. Mapping of the identified SNPs revealed 525 SNPs in candidate genes related to production traits while 333 SNPs were mapped to candidate genes related to reproduction traits. The SNPs identified in this study will facilitate further insights on tropical adaptation, domestication history and population structure of indigenous cattle. The variants in candidate genes identified in this study will serve as useful genetic tools, in the quest for phenotype modifying nucleotide change and help in designing appropriate genetic improvement programs.

Candidate SNP of CACNA2D1 Gene Associated with Clinical Mastitis and Production Traits in Sahiwal (Bos taurus indicus) and Karan Fries (Bos taurus taurus × Bos taurus indicus).

The present study was conducted to identify polymorphisms in CACNA2D1 gene and their association with clinical mastitis and production traits. Exon 18 and its flanking regions were screened for the presence of SNPs. Statistical analysis was performed to identify association of period of birth, breed, and genotype with mastitis incidence on randomly selected 103 Sahiwal and 102 Karan Fries cattle. PCR-RFLP analysis revealed that g.38819398G > A mutation in exon 18 (269 bp amplicon) of CACNA2D1 gene resolved into AA, AG, and GG genotypes in Sahiwal and Karan Fries cattle. Wald chi-square analysis revealed that the period of birth, breed, and genotype were significantly associated with mastitis incidence. GG genotyped cattle were found to be less susceptible to mastitis. Least square analysis revealed that GG and AG genotype animals of G38819398A SNP of CACNA2D1 gene in Sahiwal as well as in Karan Fries cattle were associated with higher average milk yields during 1st, 2nd, and 3rd lactations (P < 0.01). These observations and their differential association with the incidence of mastitis and production traits can be utilized as an aid to selection for simultaneous improvement of both antagonistic traits; however, validation of results on large number of animals is warranted.

Genomewide identification and annotation of SNPs in Bubalus bubalis.

The present study was carried out to identify and annotate the genome wide SNPs in Murrah buffalo genome. A total of 21.2 million raw reads from 4 pooled female Murrah buffalo samples were obtained using restriction enzyme digestion followed by sequencing with Illumina Hiseq 2000. After quality filtration, the reads were aligned to Murrah buffalo genome (ICAR-NBAGR) and Water buffalo genome (UMD_CASPUR_WB_2.0) which resulted in 99.37% and 99.67% of the reads aligning, respectively. A total of 130,688 high quality SNPs along with 35,110 indels were identified versus the Murrah bufffalo genome. Similarly 219,856 high quality SNPs along with 15,201 indels were identified versus the Water buffalo genome. We report 483 SNPs in 66 genes affecting Milk Production, 436 SNPs in 38 genes affecting fertility and 559 SNPs in 72 genes affecting other major traits. The average genome coverage was 13.4% and 14.8% versus the Murrah and Water buffalo genomes, respectively.

Molecular characterization and SNP identification in HSPB6 gene in Karan Fries (Bos taurus x Bos indicus) cattle.

Heat shock proteins (HSPs) act as molecular chaperones which are preferentially transcribed in response to severe perturbations of the cellular homeostasis such as heat stress. The present study was undertaken for molecular characterization and detection of genetic polymorphisms of HSPB6 gene in 100 Karan Fries Cattle. HSPB6 gene was mapped on Bos taurus autosome 18 (BTA 18), comprising three exons and two introns. Four sets of primers for HSPB6 gene were designed using Primer3 software (version 0.4.0). For detecting single nucleotide polymorphisms (SNPs), sequence data was analyzed using BioEdit software (version 7.2). Comparative sequence analysis of HSPB6 gene showed five nucleotide polymorphisms, which included three transitions viz. g.161A > G, g.436G > A and g.2152A > G and two transversions viz. g.1743C > G and g.2417A > T compared to B. taurus (NCBI GenBank: AC_000175.1). HSPB6 gene of Karan Fries cattle exhibited a high percentage of nucleotide identity (47.0-100.0%) with the corresponding mammalian homologue. The present study indicated a high degree of genetic variability in the HSPB6 gene in the Karan Fries cattle populations.

Identification of single nucleotide polymorphism in protein phosphatase 1 regulatory subunit 11 gene in Murrah bulls.

AIM: This study was conducted with the objective to identify single nucleotide polymorphism (SNP) in protein phosphatase 1 regulatory subunit 11 (PPP1R11) gene in Murrah bulls. MATERIALS AND METHODS: Genomic DNA was isolated by phenol-chloroform extraction method from the frozen semen samples of 65 Murrah bulls maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal. The quality and concentration of DNA was checked by spectrophotometer reading and agarose gel electrophoresis. The target region of PPP1R11 gene was amplified using four sets of primer designed based on Bos taurus reference sequence. The amplified products were sequenced and aligned using Clustal Omega for identification of SNPs. Animals were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using EcoNI restriction enzyme. RESULTS: The sequences in the NCBI accession number NW_005785016.1 for Bubalus bubalis were compared and aligned with the edited sequences of Murrah bulls with Clustal Omega software. A total of 10 SNPs were found, out of which 1 at 5'UTR, 3 at intron 1, and 6 at intron 2 region. PCR-RFLP using restriction enzyme EcoNI revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study. CONCLUSION: A total of 10 SNPs were found. PCR-RFLP revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study, due to which association analysis with conception rate was not feasible.

Hemin, a heme oxygenase-1 inducer, restores the attenuated cardioprotective effect of ischemic preconditioning in isolated diabetic rat heart.

BACKGROUND: Attenuated cardioprotective effect of ischemic preconditioning (IPC) by reduced nitric oxide (NO) is a hallmark during diabetes mellitus (DM). Recently, we reported that the formation of caveolin-endothelial nitric oxide synthase (eNOS) complex decreases the release of NO, which is responsible for attenuation of IPC-induced cardioprotection in DM rat heart. Heme oxygenase-1 (HO-1) facilitates release of NO by disrupting caveolin-eNOS complex. The activity of HO-1 is decreased during DM. This study was designed to investigate the role of hemin (HO-1 inducer) in attenuated cardioprotective effect of IPC in isolated diabetic rat heart. METHODS: DM was induced in male Wistar rat by single dose of streptozotocin. Cardioprotective effect was assessed in terms of myocardial infarct size and release of lactate dehydrogenase and creatine kinase in coronary effluent. The release of NO was estimated indirectly by measuring the release of nitrite in coronary effluent. Perfusion of sodium nitrite, a precursor of NO, was used as a positive control. RESULT: IPC-induced cardioprotection and increased release of nitrite were significantly attenuated in a diabetic rat as compared to a normal rat. Pretreatment with hemin and daidzein, a caveolin inhibitor, alone or in combination significantly restored the attenuated cardioprotection and increased the release of nitrite in diabetic rat heart. Zinc protoporphyrin, a HO-1 inhibitor, significantly abolished the observed cardioprotection and decreased the release of nitrite in hemin pretreated DM rat heart. CONCLUSION: Thus, it is suggested that hemin restores the attenuated cardioprotective effect in diabetic rat heart by increasing the activity of HO-1 and subsequently release of NO.