The Effects Of Low Dose X-ray On The Epididyma Sperm Cells Of Rats

 This study examines the effects of low dose x-rays on the pH, sperm count, and sperm motility of the epididymal sperm cells of wistar rats. An experimental survey (case control study design) was adopted and a purposive sampling technique was used to select the species of mammals used for the experiment while a convenient sampling technique was used to select a nearby animal farm and a simple random technique was used to select the population of the male rats used. The population were divided into three test groups and a control group with test groups exposed to x-rays using a stationary x-ray machine and their epididymis extracted with a dissecting set and pH, sperm count and motility checked using a pH meter ( for pH) and the others performed with a microscope. Anova test was used to perform and analyze the data collected. 

Findings here showed that at low dose of x-ray:

 The pH of the epididyma sperm cell were not affected 

 The sperm count and motility of the spermatogonia and spermatocytes  were affected while the spermatozoa ( matured cells) were spared. 

This study recommends that there is need for great adhesion to the use of gonad shield in practice to avoid exposing male patients to adverse effect of radiation.

Title page .....................................................................................................i

Dedication…………………………………………………………………ii

Approval page…………………………………………………………….iii

Certification……………………………………………………………….iv

Acknowledgement…………………………………………………………v

Table of contents…………………………………………………………..vi

List of tables……………………………………………………………….vii

List of figures………………………………………………………………viii

Abstract…………………………………………………………………….ix

CHAPTER ONE: INTRODUCTION

1.1: Background of study………………………………………………….1

1.1.1 Medical procedures .............................................................................2

1.1.2 Mode of generation of x-ray.................................................................3

1.1.3 Area of utilization ................................................................................4

1.1.4 Epididymis ...........................................................................................5

1.1.5 Sperm cell .............................................................................................5

1.1.6 Biological Effects of ionizing radiation ...............................................6

1.2: Statement of Problem…………………………………………………7

1.3: Specific Objective of study……………………………………………8

1.4: Significance of study………………………………………………….8

1.5: Scope of study…………………………………………………………9

1.6: Definition of terms………………………………………..9

1.7: Literature review……………………….............................................14

CHAPTER TWO: THEORETICAL BACKGROUND

2.1: Radiation ……………………………………….............................. 16

2.2:  Sources and uses of ionizing radiation…………………………………23………..

2.2.1: Radiation Dose …………………………………………………………24

2.3 Reproductive Anatomy Of Rats  …………………………………………26…..

2.3.1 Reproduction Organ …………………………………………26

2.4  Production of sperm cells ( spermatozoa) …………………………35

2.4 .1 Factors Influencing sperm cell production……………………...........36

2.5 Evaluation of sperm cell ………………………………………….38

CHAPTER THREE: RESEARCH METHODOLOGY

3.1: Experimental Animals……………………………………...........40

3.2: Research Design…………………………………………………40

3.3: Sampling Technique…………………………….........................41

3.3.1: Selection Criteria……………………………………………...41

3.3.2: Sampling Size…………………………………………………42

3.4: Instrumentation/ Materials………………………………………42

3.5: Conduct of Study……………………………………………......43

3.6: Method of Data Analysis………………………………………46

CHAPTER FOUR: RESULTS

4.1: Data presentation…………………………………………………….47

CHAPTER FIVE: DISCUSSION AND IMPLICATIONS OF RESULTS, CONCLUSION AND RECOMMENDATIONS

5.1: Discussion ...............................................……………………………….64

5.1.1: Objective I ( the effects of low dose x-ray on pH of epididyma sperm cell)...........................64

5.1.2: Objective II (the effects of low dose x-ray on sperm count of epididyma sperm cell)..65

5.1.3: Objective 2 (the effects of low dose x-ray on sperm motility of epididyma sperm cell)…………………............ 66

5.1.3: Objective 3 (the effects of low dose x-ray on sperm motility of epididyma sperm cell)………………………………..

5.2: summary and conclusion ..................................................................................67

5.3: recommendations ..............................................................................................68

5.4: areas for further study........................................................................................68

5.5: Limitation of study .............................................................................................69

References...................................................................................................................70

Appendix ................................................................................................................... 73

Table 1: One-way Anova test of pH for the control and test group................................... 47 

Table 2: One-way Anova test of sperm count for the control and test group......................49

Table 3: One-way Anova test of sperm motility for the control and test group................. 52

Table 4: the distribution of the mean± S.E.M of the parameters in the various groups following their days after exposure..56

Table 5: one-way ANOVA test of pH for the different days after exposure to x-ray....... 58

Table 6: one-way ANOVA test of sperm count for the different days after exposure to x-ray.....59

Table 7: one-way ANOVA test of sperm motility for the different days after exposure to x-ray................................ 60

Table 8: the distribution of the mean± S.E.M of the parameters in the various days after exposure  following the different groups 62

Fig 1: the reproductive system of male rats ...................................... 30 

Fig 2: heads of released sperm from three species .............................. 34

Fig 3: Stages in the formation of sperm cells ........................................ 35

Fig 4: clustered out sperm cells when viewed under the microscope ........46

Fig 5: Spaced out sperm cells when viewed under the microscope ............ 46

Fig 6: line graph shows the pH  variation in the different groups after different time of exposure ..........48

Fig 7: line graph shows the sperm count variation in the different groups after different time of exposure ...........................................51

Fig 8: line graph shows the motility variation in the different groups after different time of exposure ....................................54

There are many sources of harmful radiation. Industrial radiographers are mainly concerned with exposure from x-ray generators and radioactive isotopes, but let's start by considering sources of radiation in general. It is important to understand that eighty percent of human exposure comes from natural sources such as outer space, rocks and soil, radon gas, and the human body. The remaining twenty percent comes from man-made radiation sources, such as those used in medical and dental diagnostic procedures1.

One source of natural radiation is cosmic radiation. The earth and all living things on it are constantly being bombarded by radiation from space. The sun and stars emits EM radiation of all wavelengths1. Charged particles from the sun and stars interact with the earth’s atmosphere and magnetic field to produce a shower of radiation, typically beta and gamma radiation. The dose from cosmic radiation varies in different parts of the world due to differences in elevation and the effects of the earth’s magnetic field. 

There are also a number of manmade radiation sources that present some exposure to the public. Some of these sources include tobacco, television sets, smoke detectors, combustible fuels, certain building materials, nuclear fuel for energy production, nuclear weapons, medical and dental X-rays, nuclear medicine, X-ray security systems and industrial radiography. By far, the most significant source of man-made radiation exposure to the average person is from medical procedures, such as diagnostic X-rays, nuclear medicine, and radiation therapy1.

Medical diagnostic procedures used to define and diagnose medical conditions are currently the greatest man-made source of ionizing radiation exposure to the general population. However, even these sources are generally quite limited compared to the general background radiation on Earth.

The risks and benefits of radiation exposure due to medical imaging and other sources must be clearly defined for clinicians and their patients. This work is a general overview for the population, who should understand the fundamentals of medical ionizing radiation and the general associated risks especially on epididyma sperm cell. This work will also acquaint the practitioner with relative doses of common radiographic procedures as well as natural background radiation.

The use of ionizing radiation in medicine began with the discovery of x-rays by Roentgen in 1895. Ionizing radiation is the portion of the electromagnetic spectrum with sufficient energy to pass through matter and physically dislodge orbital electrons to form ions. These ions, in turn, can produce biological changes when introduced into tissue2.

 Ionizing radiation can exist in 2 forms: 

i. As an electromagnetic wave;

 This include x-ray or gamma ray. 

ii. As a particle;

This may be in the form of an alpha or beta particle, neutron, or proton.

X-rays are machine-generated, it is produced when rapidly moving electrons that have been accelerated through a potential difference of the order of 10-3 to 10-6 volts are allowed to strike a metal target. The kinetic energy of the electrons is converted in 3 principal way.

1. Less than 1% is converted to x-radiation

2. Approximately 99% is converted into heat by increasing the thermal vibration of the atom of the target which may rise considerably.

Meanwhile gamma rays are electromagnetic waves that are emitted from the nucleus of an unstable atom. Different forms of ionizing radiation have differing abilities to generate biologic damage

   x-rays can further be divided into either;

i) Hard radiation

ii) Soft  radiation

Based on the dosage given, it can either;

This are doses that ranges from 1rad to 20rads. This is normally encountered in diagnostic field. Though low, they tend to have effects on many sensitive organs of the body and these doses can be received in various different ways. This work is out to investigate the effect these low dose x-radiation (which are received in diagnostic radiation) on the various semen parameters

These dosage are measured in sievert and its effects is dependent on the specie being studied.

 1) Head or caput epididymis- it is the proximal part of the epididymis. It caries the sperms from the testis. 

2) Body or corpus epididymis- it the highly convoluted middle part of the epididymis 

3) Tail or cauda epididymis- it is the last part that takes part in carrying the sperms to the vas deferens. Epididymis keeps sperms for sometimes, gives nourishment to it. The cauda epididymis continues to form less convoluted vas deferens3.

Radiation damages the cell by damaging DNA molecules directly through ionizing effects on DNA molecules or indirectly through free radical formation. A lower dose delivered through a long period of time theoretically allows the body the opportunity to repair itself. Radiation damage may not cause any outward signs of injury in the short term; effects may appear much later in life5            

Deterministic effects, such as cell killing, can be more immediate and have a threshold above which severity increases with radiation dose. However, the threshold is not necessarily the same in each individual or tissue. While healing may ensue, necrosis and fibrotic changes in internal organs, acute radiation sickness, cataracts, and sterility may also occur. For acute deterministic effects, large doses are usually required, such as 1-2 Gy or 1-2 Sv. 

Stochastic effects, such as mutations, can result in cancer and hereditary effects. Cancer induction can have a long latency period. Estimating cancer risks associated with diagnostic x-rays using epidemiological tools is difficult because of extrapolation to low radiation doses, recall bias, and different x-ray energies used at various kiinstitutions. Most low-dose human ionizing radiation risk estimates come from the atomic bomb survivors in Japan. Other sources of information include laboratory cellular mutation studies and studies on various strains of mice; of course, the applicability to humans remains to be seen.

Finally other main consequences of radiation are hereditary effects. Radiation damage to the gonads during the reproductive period of life produces mutations to the gametes. Inherited diseases can encompass a range of mild disorders to serious consequences, including death or severe mental defects. However, no human population studies have shown hereditary effects from typical background ionizing radiation doses. Furthermore, some studies of the offspring of atomic bomb survivors have not shown statistically significant increases in hereditary defects or cancers5.